ABO NOCE Basic Opticianry Exam — Questions and Answers

Question 1: The angle of the anterior chamber is formed by the junction of the:

Iris and cornea (Correct answer)
Sclera and retina
Choroid and iris
Cornea and lens

Correct answer: Iris and cornea

The iridocorneal angle (anterior chamber angle) is formed where the peripheral iris meets the posterior cornea, and it contains the trabecular meshwork.

Question 2: In the ANSI Z80.1 standard, what is the tolerance for sphere power for a lens with a power of -4.00 D?

±0.25 D
±0.13 D
±0.12 D (Correct answer)
±0.06 D

Correct answer: ±0.12 D

ANSI Z80.1 allows ±0.12 D sphere power tolerance for lenses with powers between 0.00 and -6.50 D.

Question 3: A patient with Rx OD: +2.00 DS, OS: +4.00 DS looks 10 mm down to read. What is the vertical imbalance?

1.0Δ
6.0Δ
4.0Δ
2.0Δ (Correct answer)

Correct answer: 2.0Δ

First, calculate the prism for each eye. OD: P = (1.0 cm) * (2.00 D) = 2.0Δ BD. OS: P = (1.0 cm) * (4.00 D) = 4.0Δ BD. Since both bases are in the same direction, the imbalance is the difference between them: 4.0Δ - 2.0Δ = 2.0Δ.

Question 4: When two thin lenses are placed in contact with each other, the combined power is:

The product of their individual powers
Determined by the separation distance only
Always less than either individual power
The algebraic sum of their individual powers (Correct answer)

Correct answer: The algebraic sum of their individual powers

For thin lenses in contact (zero separation), the combined power equals the algebraic sum: F_total = F1 + F2.

Question 5: When adjusting a stainless steel frame that has been coated with a colored epoxy finish, the optician must be careful to:

Submerge the frame in acetone to remove the coating before adjusting
Avoid using abrasive tools or excessive bending that could crack or peel the coating (Correct answer)
Heat the frame to 350°F to soften the coating before bending
Always replace the frame rather than adjusting it

Correct answer: Avoid using abrasive tools or excessive bending that could crack or peel the coating

Epoxy or painted coatings on metal frames are vulnerable to cracking if bent too sharply or abraded by tools, leaving unsightly bare metal exposed.

Question 6: Transpose -0.25 -0.75 x 135 into plus cylinder form.

-1.00 -0.75 x 045
+0.75 -0.75 x 045
-0.25 +0.75 x 045
-1.00 +0.75 x 045 (Correct answer)

Correct answer: -1.00 +0.75 x 045

New sphere = -0.25 + (-0.75) = -1.00; new cyl = +0.75; new axis = 135 - 90 = 045.

Question 7: A patient's nylon (polyamide) frame is adjusted in the office, but by the next day the adjustment has partially relaxed. The optician should explain that:

The patient must have bent the frame themselves
Nylon frames hold adjustments permanently once cooled
Nylon has inherent flexibility and may require follow-up adjustment, and results are often less stable than with acetate (Correct answer)
The frame is defective and must be returned to the manufacturer

Correct answer: Nylon has inherent flexibility and may require follow-up adjustment, and results are often less stable than with acetate

Nylon (polyamide) frames have high elasticity and may gradually creep back toward their original shape, making durable adjustments more challenging than with acetate.

Question 8: A licensed optician in a state that permits prescription modifications within certain tolerances adjusts the cylinder axis by 5 degrees to improve a patient's comfort. This action is:

Only permissible if the patient signs an informed consent form
Potentially permissible if within the state-defined tolerances and regulations (Correct answer)
Always a scope violation regardless of state law
Always permissible as a frame/fit adjustment

Correct answer: Potentially permissible if within the state-defined tolerances and regulations

Some states grant licensed opticians limited authority to make minor prescription modifications within defined tolerances; such adjustments may be permissible depending on state law.

Question 9: A frame marked 54-18-140 has what bridge size?

18 mm (Correct answer)
36 mm
140 mm
54 mm

Correct answer: 18 mm

In standard frame notation (eye size–bridge–temple length), the middle number (18) is the bridge width.

Question 10: A patient reports that their AR-coated lenses have developed 'crazing' — a network of fine cracks in the coating. What is the most likely cause?

Minor impact from a small drop
Insufficient UV exposure during the coating curing process
Exposure to heat, such as leaving glasses in a hot car (Correct answer)
Using lens cleaning spray too frequently

Correct answer: Exposure to heat, such as leaving glasses in a hot car

Heat causes the lens substrate and the AR coating to expand at different rates (different coefficients of thermal expansion), leading to stress and crazing or micro-cracking of the coating.

Question 11: Meniscus, equiconcave, and flat concave are varieties of

Minus lenses (Correct answer)
spherocylinder lenses
Plus lenses
Astigmatic lenses

Correct answer: Minus lenses

Meniscus, equiconcave, and flat concave (or plano-concave) are all types of concave lenses. Concave lenses are thinner in the center and thicker at the edges, causing light rays to diverge. These lenses are used to correct myopia (nearsightedness) and are therefore classified as minus lenses, having negative dioptric power.

Question 12: A patient requires a high plus prescription. To minimize magnification and improve cosmetics, the optician should recommend:

Standard index CR-39 in any frame
Large frame with high index material
Large frame with polycarbonate
Small frame with aspheric high index lens (Correct answer)

Correct answer: Small frame with aspheric high index lens

A small frame with aspheric high index lenses reduces center thickness and minimizes the magnification commonly seen with high plus prescriptions.

Question 13: Prism thinning is a technique used primarily to:

Reduce chromatic aberration
Equalize the center thickness of lenses with different powers (Correct answer)
Correct a vertical phoria
Increase the optical power of the lens

Correct answer: Equalize the center thickness of lenses with different powers

Prism thinning (slab-off or base-up prism) compensates for the differential prismatic effect in anisometropic corrections, but in lens fabrication, 'prism thinning' typically refers to equalizing thickness.

Question 14: Which photopigment is found in rod photoreceptors?

Erythrolabe
Rhodopsin (Correct answer)
Chlorolabe
Cyanolabe

Correct answer: Rhodopsin

Rods contain rhodopsin (visual purple), a photopigment maximally sensitive to wavelengths around 498 nm and critical for scotopic (dim-light) vision.

Question 15: The American National Standards Institute (ANSI) Z80.1 standard specifies that the allowable tolerance for sphere power in a finished lens (powers above ±6.50 D) is:

±0.37 D
±0.25 D
±0.13 D
2% of the stated power (Correct answer)

Correct answer: 2% of the stated power

ANSI Z80.1 allows ±2% of the stated power for lenses with sphere powers greater than ±6.50 D, rather than the fixed tolerance used for lower powers.

Question 16: The term 'scope of practice' for a licensed optician means:

The types of insurance plans an optician may bill
The geographic area in which an optician may legally work
The number of patients an optician may serve per day
The legally defined range of services an optician is permitted to perform (Correct answer)

Correct answer: The legally defined range of services an optician is permitted to perform

Scope of practice defines the legally permitted range of professional activities — services an optician may perform without constituting the unauthorized practice of another profession.

Question 17: Which condition involves the lens of the eye becoming progressively opaque?

Retinal detachment
Cataract (Correct answer)
Macular degeneration
Glaucoma

Correct answer: Cataract

A cataract is a clouding of the crystalline lens that reduces light transmission and causes blurred, hazy vision.

Question 18: A lens's power is indicated by the word "axis."

False (Correct answer)
True

Correct answer: False

The 'axis' in an eyeglass prescription refers to the orientation of the cylinder power, which corrects astigmatism. It indicates the meridian of the lens that has no cylinder power, or where the cylinder power is oriented. The lens's overall power (sphere and cylinder) is measured in diopters, not by the axis, which is an angular measurement.

Question 19: Prentice's Rule states that prism is induced whenever the eye looks through any point other than the:

Geometric center of the lens
Major reference point in a single-vision lens
Optical center of the lens (Correct answer)
Segment center of a bifocal

Correct answer: Optical center of the lens

The optical center is the only point in the lens where light passes without prismatic deviation.

Question 20: Which material requires a warm water bath or frame heater before adjustment to prevent breakage?

Beta-titanium
Titanium
Zyl (cellulose acetate) (Correct answer)
Stainless steel

Correct answer: Zyl (cellulose acetate)

Zyl (cellulose acetate) must be heated before adjustment because it becomes brittle when cold and will crack if bent without warming.

Question 21: Which refractive error is caused by the cornea or lens having different curvatures in different meridians?

Hyperopia
Myopia
Presbyopia
Astigmatism (Correct answer)

Correct answer: Astigmatism

Astigmatism occurs when the eye's refracting surfaces (usually the cornea) have different powers in different meridians, causing light to focus in two separate focal lines instead of a single point.

Question 22: What is the spherical equivalent of -3.00 +2.00 x 180?

-2.00 (Correct answer)
-1.00
-4.00
-3.00

Correct answer: -2.00

SE = -3.00 + (2.00 ÷ 2) = -3.00 + 1.00 = -2.00.

Question 23: What is the Abbe value (V-value) and what does a higher Abbe value indicate?

A measure of chromatic aberration; higher value means less chromatic aberration (Correct answer)
A measure of impact resistance; higher value means more durable
A measure of UV protection; higher value means more UV blocked
A measure of lens thickness; higher value means thicker lens

Correct answer: A measure of chromatic aberration; higher value means less chromatic aberration

Abbe value measures the dispersion of light through a lens material. Higher Abbe value (less dispersion) = less chromatic aberration = better optical clarity.

Question 24: The aqueous humor is a clear fluid that fills the anterior and posterior chambers of the eye. What is its primary drainage pathway out of the eye?

Direct absorption by the corneal endothelium
Via the uveoscleral outflow pathway
Through the vitreous humor to the optic nerve
Through the trabecular meshwork into Schlemm's canal (Correct answer)

Correct answer: Through the trabecular meshwork into Schlemm's canal

The primary, or conventional, pathway for aqueous humor drainage involves the fluid flowing from the anterior chamber through the trabecular meshwork. From there, it enters Schlemm's canal and then drains into the episcleral venous system to return to the general circulation. This pathway regulates intraocular pressure.

Question 25: In a progressive addition lens, where is the distance optical power measured?

In the fitting cross or distance reference point (DRP) (Correct answer)
At the segment top
At the prism reference point (PRP)
At the geometric center of the lens blank

Correct answer: In the fitting cross or distance reference point (DRP)

The distance power of a PAL is measured at the distance reference point (DRP) or fitting cross, which is positioned in front of the patient's pupil for distance viewing.

Question 26: The FDA classifies contact lenses as which type of medical device?

Class II or Class III medical devices regulated under 21 CFR 886 (Correct answer)
Over-the-counter devices requiring no regulation
Prescription drugs regulated under the Food, Drug, and Cosmetic Act's drug provisions
Class I devices exempt from premarket notification

Correct answer: Class II or Class III medical devices regulated under 21 CFR 886

Contact lenses are classified as Class II (daily wear soft) or Class III (extended wear) medical devices regulated by FDA under 21 CFR 886 (ophthalmic devices).

Question 27: Which muscle is responsible for constricting the pupil in bright light?

Sphincter pupillae (Correct answer)
Orbicularis oculi
Dilator pupillae
Superior rectus

Correct answer: Sphincter pupillae

The sphincter pupillae is a circular smooth muscle innervated by the parasympathetic nervous system that constricts the pupil.

Question 28: A patient needs reading glasses and asks for the strongest magnification available OTC. What is the maximum power typically found in OTC readers?

+4.00 D
+1.00 D
+2.00 D
+3.00 D (Correct answer)

Correct answer: +3.00 D

OTC reading glasses are typically available up to +3.00 D; powers above this generally require a custom prescription.

Question 29: The choroid is primarily responsible for:

Maintaining intraocular pressure
Producing aqueous humor
Providing oxygen and nutrients to the outer retina (Correct answer)
Controlling pupil size

Correct answer: Providing oxygen and nutrients to the outer retina

The highly vascular choroid supplies oxygen and nutrients to the outer one-third of the retina, including the photoreceptors.

Question 30: When verifying the optical center placement of a dispensed pair of glasses, the optician should check:

Only that the lenses are not scratched or chipped
That the frame fits correctly on the patient's face
That the OC height matches the prescribed seg/OC height and the horizontal decentration matches the patient's PD (Correct answer)
Only the sphere power of each lens

Correct answer: That the OC height matches the prescribed seg/OC height and the horizontal decentration matches the patient's PD

Verification must confirm that optical centers are placed at the correct height and horizontal position (per patient PD) per ANSI Z80.1 standards.

Question 31: What is the effect of increasing the pantoscopic tilt of a frame on the effective optical power experienced by the wearer?

It has no effect on optical power
It only affects the add power in progressives
It increases effective sphere power and induces cylinder at the horizontal meridian (Correct answer)
It decreases both sphere and cylinder power

Correct answer: It increases effective sphere power and induces cylinder at the horizontal meridian

Pantoscopic tilt tilts the optical axis downward, effectively increasing sphere power and inducing oblique cylinder.

Question 32: A patient with anisometropia experiences vertical imbalance when reading. The prescription is OD: +1.00 D sphere, OS: +4.00 D sphere, with a +2.00 Add. Assuming a reading level 10 mm below the optical centers, which of the following is the most appropriate corrective action?

Order a slab-off (bicentric grind) on the left lens.
Order a slab-off (bicentric grind) on the right lens. (Correct answer)
Prescribe single vision reading glasses only.
Increase the pantoscopic tilt to 15 degrees.

Correct answer: Order a slab-off (bicentric grind) on the right lens.

Vertical imbalance occurs when there's a significant power difference between lenses in the vertical meridian. Slab-off, a form of bicentric grinding, adds prism to correct this. The rule is to apply slab-off (Base Up prism effect) to the lens with the most minus or least plus power in the vertical meridian. In this case, the OD (+1.00 D) is the least plus lens and requires the slab-off correction.

Question 33: What is 'image jump' in a bifocal lens?

The prismatic displacement of an image that occurs as the line of sight crosses the top edge of the bifocal segment (Correct answer)
The change in apparent magnification between distance and near zones
The increase in add power as gaze moves downward into the segment
The chromatic aberration produced at the segment boundary

Correct answer: The prismatic displacement of an image that occurs as the line of sight crosses the top edge of the bifocal segment

Image jump is the sudden prismatic displacement of an object seen the instant the line of sight crosses the top of the bifocal segment. Its magnitude equals the add power multiplied by the distance (in cm) from the segment top to the segment's optical center, per Prentice's Rule.

Question 34: When verifying prescribed prism of 1.50Δ base in, ANSI Z80.1 allows a tolerance of:

±0.12Δ
±0.37Δ
±0.25Δ (Correct answer)
±5% of prescribed amount

Correct answer: ±0.25Δ

For prescribed prism of 2.00Δ or less, ANSI Z80.1 allows a tolerance of ±0.25Δ in any meridian.

Question 35: In the standard boxing system for frame measurements, what does the 'A' measurement represent?

The horizontal width of the lens box. (Correct answer)
The effective diameter of the lens.
The vertical depth of the lens box.
The distance between the lenses (bridge size).

Correct answer: The horizontal width of the lens box.

The 'A' measurement, often called the eye size, represents the widest horizontal dimension of the imaginary box drawn around the lens shape. The 'B' measurement is the vertical depth, and the DBL is the distance between lenses.

Question 36: A patient asks why their new AR-coated lenses show a faint green or purple reflection. How should you respond?

The coating is defective and the lenses should be remade
This residual reflection is normal and indicates the AR coating is functioning correctly (Correct answer)
The reflection indicates the lens index is too high for AR coating
The lenses need an additional UV coating to eliminate the color

Correct answer: This residual reflection is normal and indicates the AR coating is functioning correctly

A slight residual green or purple reflection is characteristic of a properly applied AR coating and results from the specific wavelengths of light that the multi-layer stack does not fully cancel.

Question 37: A state law requires opticians to complete 20 hours of continuing education every 2 years for license renewal. An optician who fails to meet this requirement faces:

Automatic license revocation with no appeal
A written warning only for the first offense
No consequences if they have practiced for over 10 years
Possible non-renewal or suspension of their license (Correct answer)

Correct answer: Possible non-renewal or suspension of their license

Failure to meet continuing education requirements typically results in the state board denying license renewal or suspending the license.

Question 38: The vitreous humor occupies which chamber of the eye?

Anterior chamber
Suprachoroidal space
Vitreous chamber (Correct answer)
Posterior chamber

Correct answer: Vitreous chamber

The vitreous humor fills the vitreous chamber (posterior segment), which is the large cavity behind the lens.

Question 39: Free-form (digital surfacing) lens technology primarily benefits patients by:

Reducing peripheral aberrations through customized back surface optimization (Correct answer)
Removing the need for anti-reflective coatings
Increasing the Abbe value of the lens material
Eliminating chromatic aberration entirely

Correct answer: Reducing peripheral aberrations through customized back surface optimization

Free-form technology uses computer-controlled surfacing to create a customized back surface that compensates for aberrations across the entire lens, improving peripheral clarity.

Question 40: What is the approximate axial length of the average adult human eye?

18 mm
20 mm
24 mm (Correct answer)
28 mm

Correct answer: 24 mm

The average adult eye has an axial length of approximately 24 mm from the anterior corneal surface to the retina.

Question 41: Which of the following lens materials has the HIGHEST Abbe value (least chromatic aberration)?

CR-39 plastic (Abbe ~58) (Correct answer)
1.74 high-index (Abbe ~33)
Polycarbonate (Abbe ~30)
Trivex (Abbe ~45)

Correct answer: CR-39 plastic (Abbe ~58)

CR-39 plastic has an Abbe value of approximately 58, giving it the least chromatic aberration among common spectacle lens materials.

Question 42: What is the primary optical advantage of an aspheric lens design compared to a standard spherical design, particularly in higher-powered prescriptions?

It provides inherent polarization.
It increases the specific gravity of the lens.
It eliminates all chromatic aberration.
It reduces peripheral distortions and improves aesthetics. (Correct answer)

Correct answer: It reduces peripheral distortions and improves aesthetics.

Aspheric lenses have a more complex surface curvature that gradually changes from the center to the edge. This design reduces or eliminates spherical aberration, which causes distortion when looking away from the lens center. This results in a wider field of clear vision and also allows for flatter, thinner, and lighter lenses, which is more aesthetically pleasing.

Question 43: A patient requests a frame with a very small B measurement. Which lens type will be most problematic to fit in this frame?

Plano sunwear
Flat-top 28 bifocal
Single vision distance
Progressive addition lens (Correct answer)

Correct answer: Progressive addition lens

Progressive addition lenses require adequate B measurement (vertical height) to accommodate the full progressive corridor from distance to near.

Question 44: The Geneva lens clock (lens gauge) is calibrated assuming a refractive index of:

1.523 (Correct answer)
1.740
1.600
1.498

Correct answer: 1.523

The Geneva lens clock is calibrated based on a refractive index of 1.523 (standard crown glass), so readings for high-index lenses must be corrected.

Question 45: Which U.S. federal law protects patient health information, including prescriptions and vision records, held by eye care providers?

The Eyeglass Rule (FTC 16 CFR 456)
ADA (Americans with Disabilities Act)
OSHA regulations
HIPAA (Health Insurance Portability and Accountability Act) (Correct answer)

Correct answer: HIPAA (Health Insurance Portability and Accountability Act)

HIPAA's Privacy Rule protects individually identifiable health information. Eye care providers are covered entities that must protect patient records and prescriptions.

Question 46: The optic disc is considered 'blind' because it lacks which photoreceptor?

Horizontal cells
Rods only
Cones only
Both rods and cones (Correct answer)

Correct answer: Both rods and cones

The optic disc has no photoreceptors at all — it is the exit point for the optic nerve fibers.

Question 47: A lensometer drum is turned from +2.00 D to -1.50 D while focusing the cylinder lines of a lens. The cylinder power of this lens is:

-0.50 D
+0.50 D
+3.50 D
-3.50 D (Correct answer)

Correct answer: -3.50 D

Cylinder power equals the second (cylinder meridian) reading minus the first (sphere meridian) reading: -1.50 - (+2.00) = -3.50 D.

Question 48: On a lensometer, the axis scale reads in degrees from 0 to 180. When the axis drum shows 045, the cylinder axis is:

Perpendicular to the 135-degree meridian
45 degrees from horizontal (Correct answer)
The same as the 135-degree axis
45 degrees from vertical

Correct answer: 45 degrees from horizontal

An axis of 045 means the cylinder axis is oriented 45 degrees measured from the 0-degree (horizontal) meridian using the standard ANSI notation.

Question 49: What does the Bayer abrasion test measure in the context of lens coatings?

The UV transmittance through the coating stack
The impact resistance of the coated lens under drop-ball conditions
The relative scratch resistance of a coated lens compared to a standard reference (Correct answer)
The adhesion strength of the anti-reflective coating to the substrate

Correct answer: The relative scratch resistance of a coated lens compared to a standard reference

The Bayer abrasion test tumbles sand or abrasive particles against a lens and measures how much haze develops compared to a reference lens to quantify scratch resistance.

Question 50: A patient wearing +3.50 D reading glasses holds their reading material 4 cm to the right of center. How much prism is induced horizontally?

14.0Δ Base Out
0.875Δ Base Out
0Δ (Correct answer)
1.4Δ Base Out

Correct answer: 0Δ

This question is a distractor. Prentice's rule applies when the *eye* moves away from the optical center, not when the object being viewed moves. As long as the patient looks straight through the optical center of the lens, no prism is induced, regardless of where the object is.

Question 51: The ora serrata is best described as:

The anterior border of the vitreous base
The central zone of the macula
The rim of the optic disc
The junction between the retina and the pars plana of the ciliary body (Correct answer)

Correct answer: The junction between the retina and the pars plana of the ciliary body

The ora serrata is the serrated anterior margin of the neurosensory retina where it transitions to the non-photosensitive pars plana.

Question 52: The purpose of a thickness caliper in opticianry is to:

Measure the pupillary distance
Measure lens center thickness and edge thickness to verify they meet ANSI Z80.1 minimum thickness requirements (Correct answer)
Gauge the diameter of the lens blank
Measure the depth of the frame groove for bevel selection

Correct answer: Measure lens center thickness and edge thickness to verify they meet ANSI Z80.1 minimum thickness requirements

Thickness calipers measure the center and edge thickness of finished lenses to ensure they meet minimum thickness requirements per ANSI Z80.1 and are safe for dispensing.

Question 53: A patient is refracted with a prescription of -12.00 D at a vertex distance of 10mm. If their new glasses are fit with a vertex distance of 14mm, what compensated power should be ordered to provide the same effective power?

-12.00 D
-12.50 D (Correct answer)
-13.00 D
-11.50 D

Correct answer: -12.50 D

When a high-power minus lens is moved further away from the eye (an increase of 4mm in this case), it becomes effectively weaker. To compensate for this, a stronger (more minus) power must be ordered. Using the compensation formula, the new power is approximately -12.52 D. The closest standard power is -12.50 D.

Question 54: In lensometry, the difference in drum readings between the two focal lines of a cylindrical lens indicates the:

Add power
Cylinder power (Correct answer)
Sphere power
Prism power

Correct answer: Cylinder power

The numerical difference between the two power drum readings when each focal line is clear represents the cylinder power of the lens.

Question 55: How is the full add power of a progressive lens accurately measured with a lensometer?

By reading the temporal engraving on the lens
By measuring the power at the fitting cross
By subtracting the distance sphere power from the near sphere power (Correct answer)
By measuring the power difference between the top and bottom edge of the lens

Correct answer: By subtracting the distance sphere power from the near sphere power

The add power is the difference in spherical power between the near reference point (NRP) and the distance reference point (DRP). The optician must first measure the distance power, then move the lens up to the NRP and measure the new spherical power, with the difference being the add.

Question 56: Which factor most significantly affects the cosmetic appearance (thickness) of plus lenses?

Lens refractive index and frame size combined (Correct answer)
Frame size and shape only
The lens material's specific gravity
The type of anti-reflective coating selected

Correct answer: Lens refractive index and frame size combined

Center thickness in plus lenses is primarily determined by both the refractive index of the material (higher index = thinner) and the frame size (larger frame = thicker lens).

Question 57: The fovea centralis is located within which structure of the eye?

Macula lutea (Correct answer)
Optic disc
Peripheral retina
Ciliary body

Correct answer: Macula lutea

The fovea centralis is the central pit of the macula lutea and provides the sharpest central vision.

Question 58: A PD ruler is being used to measure a patient's binocular distance PD. The ruler should be aligned:

From the outer edge of one cornea to the inner edge of the other cornea
From the outer edge of one iris to the outer edge of the other iris
From the center of one pupil to the center of the other pupil (Correct answer)
From the inner edge of one iris to the outer edge of the other iris

Correct answer: From the center of one pupil to the center of the other pupil

PD is the distance between the centers of the two pupils and must be measured center-to-center for accurate optical alignment.

Question 59: Which statement BEST describes the relationship between lens power and center thickness for a minus lens?

Center thickness is unrelated to prescription power
Higher minus power requires greater center thickness to maintain edge strength
Higher minus power allows thinner center thickness but produces thicker edges (Correct answer)
Higher minus power requires thicker center AND thicker edges

Correct answer: Higher minus power allows thinner center thickness but produces thicker edges

Minus lenses are thinnest at the center and thickest at the edges; as minus power increases, the center can be made thinner but the edges become progressively thicker.

Question 60: Pantoscopic tilt refers to the angle formed between the lens plane and:

The temporal bone
The bridge of the nose
A vertical plane perpendicular to the line of sight (Correct answer)
The horizontal plane of the floor

Correct answer: A vertical plane perpendicular to the line of sight

Pantoscopic tilt is the forward tilt of the lens plane measured from a vertical reference, typically 8–12° for most prescriptions.

Question 61: Which law states that the angle of incidence equals the angle of reflection?

Law of Reflection (Correct answer)
Fermat's Principle
Prentice's Rule
Snell's Law

Correct answer: Law of Reflection

The Law of Reflection states that when light hits a surface, the angle of incidence equals the angle of reflection measured from the normal.

Question 62: Which property of a photochromic lens determines how dark it becomes in sunlight?

The concentration and type of photochromic molecules embedded in the lens (Correct answer)
The index of refraction of the lens material
The thickness of the anti-reflective coating applied over the photochromic layer
The base curve of the lens

Correct answer: The concentration and type of photochromic molecules embedded in the lens

The darkening depth of photochromic lenses depends on the density and chemical nature of the silver halide or organic photochromic molecules within the lens.

Question 63: Per ANSI Z80.1, what is the maximum allowable induced prism at the MRP for a single-vision lens with power greater than ±3.375 D?

1.00Δ
0.67Δ (Correct answer)
1.50Δ
0.33Δ

Correct answer: 0.67Δ

ANSI Z80.1 allows a maximum of 0.67Δ at the MRP for lenses stronger than ±3.375 D due to greater sensitivity to OC displacement.

Question 64: A lens with a power of -3.00 D will cause light rays to:

Converge to a focal point 33 cm behind the lens
Converge to a focal point 33 cm in front of the lens
Diverge as if from a point 33 cm in front of the lens (Correct answer)
Have no effect on vergence

Correct answer: Diverge as if from a point 33 cm in front of the lens

A minus (concave) lens diverges light, with its virtual focal point located at 1/3 m = 33 cm in front of the lens.

Question 65: The blind spot in the visual field corresponds to which ocular structure?

Optic disc (Correct answer)
Ora serrata
Peripheral retina
Fovea centralis

Correct answer: Optic disc

The optic disc (where the optic nerve exits) has no photoreceptors, creating the physiological blind spot in the visual field.

Question 66: A keratometer (ophthalmometer) is used to measure:

The thickness of the crystalline lens
The refractive power of the entire eye
Intraocular pressure
The curvature of the anterior corneal surface (Correct answer)

Correct answer: The curvature of the anterior corneal surface

The keratometer measures the radius of curvature of the anterior corneal surface, typically used for contact lens fitting.

Question 67: The power cross for -1.00 DS shows which values in both meridians?

-1.00 in both meridians (Correct answer)
0.00 in both meridians
-1.00 in one and 0.00 in the other
+1.00 in one meridian only

Correct answer: -1.00 in both meridians

A spherical lens (DS) has the same power in every meridian, so both principal meridians on the power cross read -1.00.

Question 68: When using a lensmeter to measure a bifocal lens, the reading through the segment gives the:

Distance power only
Prism at the optical center
Add power only (the difference from distance)
Near power only (Correct answer)

Correct answer: Near power only

Reading through the bifocal segment on the lensometer yields the total near power; the add power is calculated as near power minus distance power.

Question 69: What is the primary advantage of titanium frames over standard metal frames?

High strength-to-weight ratio and corrosion resistance (Correct answer)
Better flexibility for sports use
Lower cost and easier adjustment
Easier soldering for repairs

Correct answer: High strength-to-weight ratio and corrosion resistance

Titanium offers exceptional strength with very low weight, and it is highly resistant to corrosion and hypoallergenic, making it ideal for sensitive patients.

Question 70: An optician in a licensed state allows an unlicensed employee to independently fit and dispense eyeglasses to patients. This action most likely constitutes:

Acceptable delegation under supervision rules
Permitted under FTC Eyeglass Rule exemptions
A minor administrative infraction only
Aiding and abetting unlicensed practice (Correct answer)

Correct answer: Aiding and abetting unlicensed practice

Allowing an unlicensed individual to independently perform licensed acts can constitute aiding and abetting unlicensed practice, which is a violation of state law.

Question 71: A patient's photochromic lenses do not darken adequately when driving. What is the most likely explanation?

Cold temperatures inhibit the photochromic reaction
The lenses are outdated and the photochromic molecules have degraded
The lenses were manufactured with insufficient photochromic dye concentration
Automotive windshields block most UV light, which is required to activate photochromic lenses (Correct answer)

Correct answer: Automotive windshields block most UV light, which is required to activate photochromic lenses

Standard automotive windshields are laminated with UV-blocking interlayers, preventing the UV light needed to trigger photochromic darkening from reaching the lenses.

Question 72: What is the recommended minimum prescription power at which vertex distance compensation becomes clinically significant?

±5.00 D (Correct answer)
±2.00 D
±3.00 D
±4.00 D

Correct answer: ±5.00 D

Vertex distance compensation is generally considered clinically significant at ±5.00 D or higher, where small distance changes meaningfully affect effective power.

Question 73: A patient presents with a high-power prescription (-11.50 D) that was refracted at a vertex distance of 12mm. The chosen frame will sit at a vertex distance of 15mm. Which instrument is essential for the optician to use to ensure the compensated lens power is calculated correctly?

Lens Clock
Pupilometer
Distometer (Correct answer)
Polariscope

Correct answer: Distometer

A distometer (or vertexometer) is specifically designed to measure the vertex distance, which is the distance from the back surface of the lens to the front of the cornea. For prescriptions generally greater than +/- 4.00 or 5.00 D, a change in vertex distance between the refraction and the as-worn position can significantly alter the effective power of the lens. Therefore, measuring this distance accurately with a distometer is crucial for calculating the necessary power compensation.

Question 74: What is the primary purpose of frame adjustments at the pantoscopic tilt?

To improve the cosmetic appearance of the frame
To reduce the frame weight on the nose
To prevent the frame from sliding
To align the optical axis of the lens with the patient's visual axis (Correct answer)

Correct answer: To align the optical axis of the lens with the patient's visual axis

Pantoscopic tilt angles the bottom of the frame forward to align the lens optical axis with the patient's line of sight during normal reading posture.

Question 75: A lens with a 1.74 high-index material is compared to the same prescription in CR-39. The high-index lens will demonstrate:

Higher chromatic aberration (Correct answer)
Lower chromatic aberration
Identical chromatic aberration
No chromatic aberration with AR coating

Correct answer: Higher chromatic aberration

Higher index materials have lower Abbe values, meaning they disperse light more and produce more chromatic aberration than lower-index materials like CR-39.

Question 76: What type of lens corrects presbyopia by providing different optical zones for distance and near vision?

Single vision lens
Plano lens
Toric lens
Bifocal lens (Correct answer)

Correct answer: Bifocal lens

A bifocal lens has two distinct optical zones—one for distance and one for near—to compensate for the loss of accommodation in presbyopia.

Question 77: Transpose the following prescription into plus cylinder form: +1.50 -2.00 x 090

-0.50 -2.00 x 180
+3.50 -2.00 x 180
-0.50 +2.00 x 180 (Correct answer)
+1.50 +2.00 x 180

Correct answer: -0.50 +2.00 x 180

To transpose, first combine the sphere and cylinder powers to get the new sphere (+1.50 + -2.00 = -0.50). Second, change the sign of the cylinder (-2.00 becomes +2.00). Third, change the axis by 90 degrees (90 + 90 = 180).

Question 78: Which classification does the FDA assign to most finished prescription spectacle lenses?

Non-device consumer product
Class II medical device
Class III medical device
Class I medical device (Correct answer)

Correct answer: Class I medical device

The FDA classifies most finished prescription spectacle lenses as Class I medical devices, subject to general controls including impact resistance requirements.

Question 79: When measuring a plano lens on a lensometer, the target should be:

Displaced from center and blurred
Completely invisible
Centered and clear when the drum is at zero (Correct answer)
Centered only when the drum is at +1.00

Correct answer: Centered and clear when the drum is at zero

A plano (no power) lens does not alter the light path, so the target remains centered and clear when the power drum is set to zero.

Question 80: When a dispensary employee is exposed to a communicable disease through a patient encounter, which regulatory framework primarily governs the employer's obligations?

ANSI Z80.3
OSHA General Duty Clause (Correct answer)
FTC Health Breach Notification Rule
ANSI Z87.1

Correct answer: OSHA General Duty Clause

OSHA's General Duty Clause requires employers to maintain a workplace free from recognized hazards, including communicable disease exposure risks.

Question 81: What does 'effective diameter' (ED) represent in lens ordering?

The longest chord through the geometric center of the lens
The diameter of the smallest circle enclosing the entire lens shape (Correct answer)
The diagonal measurement of the lens shape
The horizontal width of the lens

Correct answer: The diameter of the smallest circle enclosing the entire lens shape

Effective diameter is the diameter of the smallest circle that can fully enclose the lens shape, used to determine minimum blank size needed.

Question 82: Which lens treatment reduces reflections on the lens surface by applying destructive interference coatings?

Polarized treatment
Anti-reflective (AR) coating (Correct answer)
Photochromic treatment
Hard coat

Correct answer: Anti-reflective (AR) coating

Anti-reflective (AR) coatings use thin-film interference to cancel out reflected light, reducing glare and improving light transmission.

Question 83: A patient requests their contact lens prescription from a prescriber. Under the FTC Contact Lens Rule, the prescriber must provide it:

Automatically at the end of the fitting, at no charge (Correct answer)
Only if the patient signs a liability waiver
Only after the patient pays a release fee
Within 30 days of a written request

Correct answer: Automatically at the end of the fitting, at no charge

The FTC Contact Lens Rule requires prescribers to automatically provide the prescription to patients upon completion of the fitting, free of charge.

Question 84: When an optician discovers that a lens does not meet ANSI Z80.1 tolerances, the appropriate course of action is to:

Dispense the lenses and note the deviation in the patient file
Remake or replace the lenses before dispensing (Correct answer)
Obtain patient signature acknowledging the deviation
Submit a variance request to the FDA

Correct answer: Remake or replace the lenses before dispensing

Lenses outside ANSI tolerances must be remade or replaced; dispensing out-of-tolerance lenses exposes the patient to visual harm and the optician to liability.

Question 85: The Schlemm's canal drains aqueous humor into which vascular system?

Central retinal vein
Choroidal capillaries
Vorticose veins
Episcleral veins (Correct answer)

Correct answer: Episcleral veins

Aqueous exits the trabecular meshwork into Schlemm's canal, then drains into episcleral venous collectors.

Question 86: Which of the following best describes a toric lens surface?

A surface that is perfectly flat
A surface with two different principal radii of curvature at 90° to each other (Correct answer)
A surface with continuously varying power across the entire lens
A surface with the same radius of curvature in all meridians

Correct answer: A surface with two different principal radii of curvature at 90° to each other

A toric surface has two principal meridians of different curvature oriented 90° apart, which is what creates the cylinder (astigmatic) correction.

Question 87: What is the ANSI Z80.1 tolerance for cylinder axis for a lens with a cylinder power of -1.75 D?

+/- 2 degrees (Correct answer)
+/- 3 degrees
+/- 5 degrees
+/- 7 degrees

Correct answer: +/- 2 degrees

For cylinder powers greater than 1.50 D, the ANSI Z80.1 standard for axis tolerance is +/- 2 degrees. This tighter tolerance is necessary as higher cylinder powers have a greater impact on vision with small axis deviations.

Question 88: A patient with a high minus prescription is concerned about the thick edge appearance of their lenses. Which coating decision would have NO direct effect on reducing edge thickness?

Reducing the frame eye size
Using aspheric lens design
Applying an anti-reflective coating (Correct answer)
Choosing a higher-index lens material

Correct answer: Applying an anti-reflective coating

AR coating improves the cosmetic appearance of lens edges optically by reducing reflections but does not change the physical thickness or geometry of the lens.

Question 89: What word best describes the direction change of light as it moves from one medium to another?

Reflection
Diffusion
Refraction (Correct answer)
Retraction

Correct answer: Refraction

Refraction is the phenomenon where light changes direction, or bends, as it passes from one transparent medium into another with a different optical density. This bending of light is fundamental to how lenses work, allowing them to focus or diverge light rays to form images on the retina. Reflection, in contrast, is when light bounces off a surface.

Question 90: A prism displaces light toward its:

Edge
Base (Correct answer)
Optical center
Apex

Correct answer: Base

Light bends toward the base of a prism, while the image appears displaced toward the apex.

Question 91: A lens aberration that causes light of different colors (wavelengths) to focus at different points, resulting in colored fringes around objects, is known as:

Spherical Aberration
Coma
Distortion
Chromatic Aberration (Correct answer)

Correct answer: Chromatic Aberration

Chromatic aberration is an optical effect where a lens fails to focus all colors to the same convergence point. This occurs because lenses have a different refractive index for different wavelengths of light. This dispersion of light results in colored halos or fringes around images.

Question 92: For a lens with a sphere power of +8.00 D, what is the ANSI Z80.1 tolerance for power?

4% of the power
+/- 0.25 D
2% of the power (Correct answer)
+/- 0.13 D

Correct answer: 2% of the power

For sphere powers greater than +/- 6.50 D, the ANSI Z80.1 tolerance is 2% of the specified power. In this case, the tolerance would be 8.00 * 0.02 = +/- 0.16 D.

Question 93: The limbus is defined as the junction between which two structures?

Lens and zonules
Cornea and sclera (Correct answer)
Iris and sclera
Retina and choroid

Correct answer: Cornea and sclera

The limbus is the transitional zone between the transparent cornea and the opaque white sclera.

Question 94: An optician uses a lens clock to measure the front surface of a lens and gets a consistent reading of +6.50 D in all meridians. What does this measurement represent?

The base curve of the lens (Correct answer)
The cylindrical power of the back surface
The total power of the lens
The spherical equivalent of the lens

Correct answer: The base curve of the lens

A lens clock measures the surface power of a lens. When the front surface is spherical (has the same power in all meridians), this reading is defined as the base curve. The total power would require measuring the back surface as well, and the spherical equivalent is a calculation involving both sphere and cylinder powers.

Question 95: The fovea centralis achieves its high visual acuity primarily because it contains a high density of:

Ganglion cells
Bipolar cells
Rods
Cones (Correct answer)

Correct answer: Cones

The fovea is densely packed with cones and lacks rods, enabling fine detail and color discrimination.

Question 96: Intraocular pressure (IOP) is measured with which instrument, and what is the normal range?

Keratometer; normal range is 8–15 mmHg
Tonometer; normal range is 10–21 mmHg (Correct answer)
Biomicroscope; normal range is 15–25 mmHg
Lensometer; normal range is 10–21 mmHg

Correct answer: Tonometer; normal range is 10–21 mmHg

IOP is measured with a tonometer (applanation or non-contact type). Normal IOP is 10–21 mmHg; elevated IOP is a major glaucoma risk factor.

Question 97: What does the power cross represent in ophthalmic optics?

The optical center of a lens
The lens power in the two principal meridians (Correct answer)
The prism base direction
The segment height of a bifocal

Correct answer: The lens power in the two principal meridians

A power cross is a diagram showing the power in each of the two principal (90°-apart) meridians of a lens.

Question 98: Which of the following is an optical aberration that occurs because a lens material refracts different wavelengths of light at slightly different angles, causing color fringes?

Spherical Aberration
Chromatic Aberration (Correct answer)
Barrel Distortion
Oblique Astigmatism

Correct answer: Chromatic Aberration

Chromatic aberration is caused by the dispersion of light as it passes through a lens. Because the refractive index of a material is slightly different for each wavelength (color) of light, white light is split into its spectral components, which can be perceived by the wearer as color fringes around objects.

Question 99: In a flat-top (FT-28) bifocal lens, the '28' refers to:

The total lens diameter in millimeters
The depth of the near segment in millimeters
The width of the near segment at its widest point in millimeters (Correct answer)
The distance from the segment top to the optical center in millimeters

Correct answer: The width of the near segment at its widest point in millimeters

In bifocal nomenclature, the number following the segment type designation refers to the width of the near segment at its widest point; FT-28 has a flat-top segment 28mm wide.

Question 100: What is the spherical equivalent of the prescription -3.00 -2.00 x 180?

-3.50 D
-2.50 D
-3.00 D
-4.00 D (Correct answer)

Correct answer: -4.00 D

Spherical equivalent (SE) = sphere + (cylinder ÷ 2) = -3.00 + (-2.00 ÷ 2) = -3.00 + (-1.00) = -4.00 D. The spherical equivalent represents the single sphere power that most closely approximates the mean refractive effect of a sphero-cylindrical lens.

Question 101: A lens has a specified base curve of +5.00 D. According to ANSI Z80.1, what is the acceptable range for the measured base curve?

+4.25 D to +5.75 D (Correct answer)
+4.50 D to +5.50 D
+4.75 D to +5.25 D
+4.00 D to +6.00 D

Correct answer: +4.25 D to +5.75 D

The tolerance for the manufactured front base curve of a lens is +/- 0.75 D from what is specified. Therefore, an acceptable range for a +5.00 D base curve would be from +4.25 D to +5.75 D.

Question 102: The refractive index of standard CR-39 plastic lens material is approximately:

1.40
1.74
1.60
1.50 (Correct answer)

Correct answer: 1.50

CR-39 (allyl diglycol carbonate) has a refractive index of approximately 1.499, commonly cited as 1.50.

Question 103: Under FDA regulations, impact-resistant lenses are required for all prescription ophthalmic lenses EXCEPT:

Polycarbonate lenses
Lenses that the prescriber determines are not in the patient's best interest (Correct answer)
Lenses dispensed via mail order
Lenses for patients under 18

Correct answer: Lenses that the prescriber determines are not in the patient's best interest

FDA 21 CFR 801.410 requires impact resistance but permits an exemption when the prescriber determines impact-resistant lenses are not in the patient's best interest and documents it.

Question 104: Which type of lens has exactly the same power in all meridians?

Aspheric lens
Spherical lens (Correct answer)
Toric lens
Cylindrical lens

Correct answer: Spherical lens

A spherical lens has a single uniform power in every meridian because it is formed by a section of a sphere.

Question 105: What is the purpose of a 'lenticular' lens design?

To maximize the field of view by using an aspheric periphery
To provide a multifocal correction without a visible segment line
To provide a built-in prism for strabismus correction
To reduce weight and thickness in very high-power prescriptions by limiting the full-power zone to a central optical cap (Correct answer)

Correct answer: To reduce weight and thickness in very high-power prescriptions by limiting the full-power zone to a central optical cap

Lenticular lenses have a central optical portion (the lenticular bowl or cap) containing the full prescription power, surrounded by a carrier of reduced power, dramatically reducing weight and thickness for very high prescriptions.

Question 106: Under the Fairness to Contact Lens Consumers Act (FCLCA), how long is a contact lens prescription valid by default if no expiration date is specified?

1 year (Correct answer)
3 years
6 months
2 years

Correct answer: 1 year

The FCLCA specifies a minimum validity of one year for contact lens prescriptions when no expiration date is stated.

Question 107: A plus power lens is essentially two prisms oriented in which configuration?

Apex to apex
Base to apex
Apex to base
Base to base (Correct answer)

Correct answer: Base to base

A plus lens, which converges light, can be visualized as two prisms with their bases joined together at the optical center. Light rays entering the lens are bent towards the thickest part (the base), causing them to converge. Conversely, a minus lens is like two prisms joined apex to apex.

Question 108: Which of the following is the primary legal distinction between a 'prescription' and an 'optical order' in opticianry?

There is no legal distinction; the terms are interchangeable in all states
A prescription specifies frame style; an optical order specifies only lens power
A prescription is required for sunglasses; an optical order is required for clear lenses
A prescription is written by a licensed examiner authorizing correction; an optical order is the work directive given to the lab by the dispenser (Correct answer)

Correct answer: A prescription is written by a licensed examiner authorizing correction; an optical order is the work directive given to the lab by the dispenser

A prescription is the legal document from the examiner authorizing the correction, while the optical order (or work order) is the dispenser's instructions to the laboratory.

Question 109: What is the term for the horizontal distance between the patient's pupils, used for lens alignment?

Vertex distance
Optical center height
Seg height
Pupillary distance (PD) (Correct answer)

Correct answer: Pupillary distance (PD)

Pupillary distance (PD) is the measurement in millimeters between the centers of the two pupils, used to align lens optical centers.

Question 110: The sagittal depth (sag) of a lens surface is defined as:

The thickness at the geometric center
The distance from the optical center to the lens edge
The perpendicular distance from the chord to the surface apex (Correct answer)
The radius of curvature of the surface

Correct answer: The perpendicular distance from the chord to the surface apex

Sag is the depth of the curve — the perpendicular distance from a flat chord across the lens to the curved surface.

Question 111: A lensometer measures which of the following properties of an ophthalmic lens?

Vertex power, axis, and prism (Correct answer)
Frame PD and segment height
Base curve and lens diameter
Lens thickness and weight

Correct answer: Vertex power, axis, and prism

The lensometer (focimeter) measures vertex power, cylinder axis, and prismatic power of ophthalmic lenses.

Question 112: Which of the following prescriptions is the minus cylinder equivalent of +1.50 +1.00 x 180?

+2.50 +1.00 x 090
+1.50 -1.00 x 090
+2.50 -1.00 x 090 (Correct answer)
+0.50 -1.00 x 090

Correct answer: +2.50 -1.00 x 090

New sphere = +1.50 + 1.00 = +2.50; new cyl = -1.00; new axis = 180 - 90 = 090.

Question 113: Diplopia (double vision) presenting in a patient wearing their current glasses is most appropriately addressed by the optician by:

Immediately remaking the lenses without consulting the prescriber
Prescribing prism lenses without an eye exam
Adjusting the nose pads to change the OC height
Verifying the glasses with a lensometer and checking alignment, then referring to the prescriber if glasses are within tolerance (Correct answer)

Correct answer: Verifying the glasses with a lensometer and checking alignment, then referring to the prescriber if glasses are within tolerance

The optician should first verify the glasses are correct. If within tolerance, diplopia is a clinical finding requiring referral to the prescriber for evaluation of a possible binocular vision or neurological problem.

Question 114: The lacrimal puncta are small openings located at the:

Medial canthus of each eyelid (Correct answer)
Lateral canthus of each eyelid
Posterior lid margin
Inferior fornix of the conjunctiva

Correct answer: Medial canthus of each eyelid

The lacrimal puncta are located on the medial margin of both upper and lower eyelids and drain tears into the lacrimal canaliculi.

Question 115: Which ANSI standard specifically addresses the performance requirements for occupational and educational personal eye and face protection?

ANSI Z87.1 (Correct answer)
ANSI Z80.1
ANSI Z80.3
ANSI Z80.5

Correct answer: ANSI Z87.1

ANSI Z87.1 covers performance requirements for occupational and educational eye and face protection devices.

Question 116: The primary purpose of a frame-warmer's temperature setting in dispensing is to:

Heat plastic frames to a workable temperature without burning or discoloring them (Correct answer)
Sterilize the frame before patient fitting
Dry moisture from nylon supra frames
Expand metal hinges for easier lens insertion

Correct answer: Heat plastic frames to a workable temperature without burning or discoloring them

Frame warmers maintain a controlled temperature—typically around 120–140°F—so zyl plastic becomes pliable without scorching or color change.

Question 117: Which fitting consideration is MOST important when dispensing high minus lenses to minimize edge thickness?

Increase the vertex distance
Select a frame with a small eye size (Correct answer)
Choose a large frame to increase optical area
Use a metal frame for better weight distribution

Correct answer: Select a frame with a small eye size

Smaller frames reduce the peripheral edge diameter of minus lenses, significantly decreasing edge thickness.

Question 118: OD is +2.00 D decentered 4 mm temporally; OS is +2.00 D decentered 4 mm temporally. What is the total horizontal prismatic imbalance between the eyes?

0.80Δ
1.60Δ (Correct answer)
3.20Δ
0Δ

Correct answer: 1.60Δ

Each eye: Δ = 2.00 × 0.4 = 0.80Δ; OD temporal decentration = base out OD; OS temporal decentration = base out OS; both base out means they compound, creating 1.60Δ total imbalance for vergence.

Question 119: A patient is prescribed a +2.00 add in their progressive lenses. Where does the corridor (channel) connect the distance and near zones?

Through the intermediate zone between the distance and near reference points (Correct answer)
Along the temporal edge of the lens
Directly through the optical center of the lens
Along the top edge of the lens blank

Correct answer: Through the intermediate zone between the distance and near reference points

The corridor or channel of a PAL is a narrow zone of increasing power connecting the distance zone (top) to the near zone (bottom), passing through the intermediate zone for arm's-length vision.

Question 120: What is the primary purpose of a hard coat applied to plastic ophthalmic lenses?

Reduce ultraviolet light transmission
Increase impact resistance
Improve scratch resistance (Correct answer)
Enhance anti-reflective properties

Correct answer: Improve scratch resistance

Hard coats are applied to plastic lenses to improve scratch resistance, since most plastics are inherently softer than glass.

Question 121: Pantoscopic tilt is the angle formed between the lens plane and:

The horizontal plane
The vertical plane (Correct answer)
The patient's optical axis
The pupillary plane

Correct answer: The vertical plane

Pantoscopic tilt is measured from the vertical plane; standard tilt is 8–12° with the bottom of the lens closer to the face.

Question 122: Which frame material is most commonly associated with allergic reactions in sensitive patients?

Titanium
Nickel-containing metal alloys (Correct answer)
Zyl/cellulose acetate
Nylon

Correct answer: Nickel-containing metal alloys

Nickel-containing metal alloys are the most common cause of contact dermatitis and allergic reactions in eyeglass wearers.

Question 123: During frame adjustment, acetate frames should be heated using:

Boiling water immersion
Hot sand or an air-bead frame warmer (Correct answer)
An open flame
A heat gun at maximum setting

Correct answer: Hot sand or an air-bead frame warmer

Hot sand or an air-bead frame warmer provides even, controlled heat appropriate for softening acetate without scorching or melting the material.

Question 124: While verifying a pair of finished eyewear with a manual lensometer, the optician cannot center the target mires within the reticle for the right lens, even with the lens platform centered. The target is displaced 2 rings upward and 1 ring toward the nasal side. How should the induced prism be recorded?

2Δ Base Up, 1Δ Base In (Correct answer)
2Δ Base Up, 1Δ Base Out
2Δ Base In, 1Δ Base Up
2Δ Base Down, 1Δ Base Out

Correct answer: 2Δ Base Up, 1Δ Base In

In a manual lensometer, the displacement of the target mires from the center of the reticle indicates the presence of prism. The direction of displacement is the direction of the prism's base. Each ring on the reticle typically represents one diopter of prism. An upward displacement means Base Up prism, and a displacement toward the nasal (inward) side means Base In prism. Therefore, a displacement of 2 rings up and 1 ring nasally corresponds to 2Δ Base Up and 1Δ Base In.

Question 125: What is the 'add power' in a progressive lens prescription?

The base curve of the lens
The additional plus power for near vision over the distance Rx (Correct answer)
The prismatic power at the optical center
The UV filter strength

Correct answer: The additional plus power for near vision over the distance Rx

Add power is the additional plus power required for near vision, added to the distance prescription to compensate for reduced accommodation.

Question 126: A lens with a power of +6.00 D is decentered 3 mm nasally. What is the resulting prism?

2.0Δ Base Out
2.0Δ Base In
1.8Δ Base In (Correct answer)
1.8Δ Base Out

Correct answer: 1.8Δ Base In

Using Prentice's Rule: P = cF = (0.3 cm) * (6.00 D) = 1.8Δ. Decentering a plus lens nasally moves the optical center nasally. To look through the OC, the eye would have to turn in, so the prism is Base In (BI).

Question 127: For a patient with a high minus prescription, which frame characteristic minimizes edge thickness?

Small eye size with centered PD (Correct answer)
Rimless frame with large eye size
Large eye size with a low bridge
Full-rim plastic frame with large eye size

Correct answer: Small eye size with centered PD

A small eye size minimizes the distance from the optical center to the edge, directly reducing edge thickness for minus lenses.

Question 128: All of the following are considered Seidel aberrations (monochromatic aberrations) EXCEPT:

Distortion
Chromatic Aberration (Correct answer)
Coma
Spherical Aberration

Correct answer: Chromatic Aberration

Chromatic aberration is caused by the dispersion of light as it passes through a lens material, meaning different wavelengths (colors) focus at different points. The five Seidel aberrations (spherical aberration, coma, oblique astigmatism, curvature of field, and distortion) are monochromatic, meaning they would occur even with single-wavelength light.

Question 129: What is the index of refraction of a material if light travels through it at 2.0 × 10⁸ m/s (speed of light in air = 3.0 × 10⁸ m/s)?

0.67
1.50 (Correct answer)
1.33
2.00

Correct answer: 1.50

Index of refraction n = speed of light in air / speed of light in medium = 3.0/2.0 = 1.50.

Question 130: Transpose the prescription +4.75 +0.75 x 110 into minus cylinder form.

+5.50 +0.75 x 020
+5.50 -0.75 x 020 (Correct answer)
+4.00 -0.75 x 020
+4.75 -0.75 x 020

Correct answer: +5.50 -0.75 x 020

Combine the sphere and cylinder for the new sphere: +4.75 + 0.75 = +5.50. Change the cylinder sign: -0.75. Change the axis by 90 degrees: 110 - 90 = 020. The result is +5.50 -0.75 x 020.

Question 131: Under FDA regulations, all ophthalmic lenses dispensed in the United States must be made of impact-resistant material EXCEPT when:

The patient is under age 18
A physician or optometrist determines that impact-resistant lenses are not suitable for the patient's visual needs (Correct answer)
The lens power exceeds +/-6.00 diopters
The patient has a history of eye injury

Correct answer: A physician or optometrist determines that impact-resistant lenses are not suitable for the patient's visual needs

FDA 21 CFR 801.410 allows an exception to the impact-resistance requirement only when a physician or optometrist determines that such lenses are not suitable for a particular patient's visual requirements.

Question 132: Which frame material is most commonly associated with nickel allergy reactions in patients?

Beta titanium
Monel (Correct answer)
Aluminum
Titanium

Correct answer: Monel

Monel, a nickel-copper alloy widely used in eyewear frames, is the most common source of nickel contact dermatitis in optical patients.

Question 133: A patient with a monocular PD of 35 mm OD and 33 mm OS has their segments decentered. Which eye's segment should be positioned further nasally?

Both segments are placed symmetrically
OD, because the PD is larger
Neither — seg position is unrelated to PD
OS, because the PD is smaller (Correct answer)

Correct answer: OS, because the PD is smaller

A smaller monocular PD (OS = 33 mm) means the pupil is closer to the nose, so the segment must be placed further nasally to align with the pupil.

Question 134: Which of the following would ANSI Z80.1 classify as a cosmetic defect requiring rejection of a finished lens?

Multiple scratches within the central 30 mm optical zone visible under diffuse illumination (Correct answer)
A single pinpoint bubble located 15 mm from the optical center
Slight edge tinting from heat treatment
A minor variation in base curve of ±0.25 D

Correct answer: Multiple scratches within the central 30 mm optical zone visible under diffuse illumination

ANSI Z80.1 surface quality requirements reject lenses with multiple defects such as scratches or bubbles within the central optical zone that are visible under diffuse light.

Question 135: A lensometer reading shows that the target does not center in the eyepiece even when the lens is moved horizontally. This indicates the presence of:

Sphere power
Cylinder power
Prism (Correct answer)
Add power

Correct answer: Prism

Prism causes the target to be displaced from center, and the amount of displacement indicates the prismatic power.

Question 136: An optician needs to create 2 prism diopters of base-out (BO) prism in a right lens with a power of -4.00 DS. How many millimeters, and in which direction from the patient's PD, must the lens's optical center (OC) be decentered?

8 mm nasally
5 mm nasally
5 mm temporally (Correct answer)
8 mm temporally

Correct answer: 5 mm temporally

Using Prentice's Rule (Prism = Power x Decentration(cm)), we rearrange to find decentration: Decentration(mm) = (Prism x 10) / Power. Decentration = (2 x 10) / 4 = 5 mm. For a minus lens, the OC is moved in the same direction as the desired base. To achieve base-out, the OC must be moved out, or temporally.

Question 137: What is the risk of over-heating a zyl (acetate) frame during adjustment?

The screws will seize in the barrel due to metal expansion
Surface bubbling, scorching, color fading, or permanent distortion of the frame (Correct answer)
The lenses will pop out from thermal expansion of the eye wire
The frame will become permanently flexible and lose shape retention

Correct answer: Surface bubbling, scorching, color fading, or permanent distortion of the frame

Excessive heat causes acetate to bubble, scorch, lose its surface sheen, or warp permanently, ruining the frame beyond repair.

Question 138: What is the recommended minimum center thickness for a polycarbonate lens to meet FDA drop ball impact resistance standards?

2.0 mm
3.0 mm
0.5 mm
1.0 mm (Correct answer)

Correct answer: 1.0 mm

Polycarbonate lenses must have a minimum center thickness of 1.0 mm to meet FDA impact resistance requirements, compared to 2.0 mm for glass and CR-39.

Question 139: Under what condition may an optician modify or 'interpret' a written prescription when fabricating lenses?

When the patient requests stronger lenses than prescribed
To compensate for vertex distance when high-power prescriptions are involved, per professional standards (Correct answer)
When they disagree with the prescribed power based on their experience
When the prescribed power is unavailable in stock and a close alternative is substituted

Correct answer: To compensate for vertex distance when high-power prescriptions are involved, per professional standards

Professional standards permit vertex distance compensation for high-powered prescriptions to achieve the intended optical effect at the eye.

Question 140: The Abbe number (V-number) of a lens material is used to measure which optical property?

Chromatic dispersion (Correct answer)
Index of refraction
Surface reflectance
Lens transmittance

Correct answer: Chromatic dispersion

The Abbe number indicates the degree of chromatic dispersion; a higher Abbe number means less chromatic aberration.

Question 141: What is the ANSI Z80.1 tolerance for the add power of a progressive addition lens?

±0.12 D (Correct answer)
±0.06 D
±0.25 D
±0.14 D

Correct answer: ±0.12 D

ANSI Z80.1 specifies ±0.12 D tolerance for the add power of progressive addition lenses.

Question 142: For a -2.00 D lens, the optical center is decentered 10 mm nasally in front of the right eye. What is the prismatic effect and base direction?

0.20Δ base in
2.00Δ base out (Correct answer)
2.00Δ base in
0.20Δ base out

Correct answer: 2.00Δ base out

Δ = 2.00 × 1.0 = 2.00Δ; for a minus lens decentered nasally in the right eye, prism base points toward the decentration = base out.

Question 143: A patient presents with loss of the temporal visual field in both eyes. The lesion most likely involves the:

Right occipital cortex
Left optic nerve
Left optic tract
Optic chiasm (Correct answer)

Correct answer: Optic chiasm

Bitemporal hemianopia is the classic presentation of an optic chiasm lesion affecting the crossing nasal fibers from both eyes.

Question 144: Which of the following best describes the scope of practice difference between an optician and an optometrist?

Opticians may perform refractions; optometrists may not dispense eyewear
Opticians may prescribe corrective lenses but not contact lenses
Both opticians and optometrists are authorized to diagnose eye disease
Optometrists may perform eye exams and write prescriptions; opticians may not (Correct answer)

Correct answer: Optometrists may perform eye exams and write prescriptions; opticians may not

Optometrists are licensed to examine eyes, diagnose conditions, and write prescriptions, while opticians are licensed to interpret and fill those prescriptions.

Question 145: A patient's frame has a B measurement of 32 mm and they require a flat-top 28 bifocal. The seg height is ordered at 17 mm. This placement positions the seg top:

Above the lower lid margin
At the geometric center of the lens
Below the lower lid margin (Correct answer)
At the lower lid margin

Correct answer: Below the lower lid margin

With a 32 mm B measurement and 17 mm seg height, the segment top is 15 mm from the bottom, which typically falls at or just below the lower lid margin.

Question 146: The uvea consists of which three structures?

Iris, ciliary body, and choroid (Correct answer)
Sclera, episclera, and conjunctiva
Cornea, lens, and retina
Optic nerve, retina, and vitreous

Correct answer: Iris, ciliary body, and choroid

The uveal tract is the vascular middle layer of the eye comprising the iris anteriorly, the ciliary body, and the choroid posteriorly.

Question 147: A patient completes their eye exam and requests a copy of their prescription to purchase glasses elsewhere. The optical's policy is to charge a $25 fee for prescription release to non-purchasing patients. According to the Federal Trade Commission (FTC) Eyeglass Rule, this policy is:

Permissible, but the fee cannot exceed $10.
Not permissible, unless the patient signs a waiver acknowledging the fee.
Permissible, as long as the fee is clearly posted.
Not permissible, as a prescription must be provided automatically and without charge. (Correct answer)

Correct answer: Not permissible, as a prescription must be provided automatically and without charge.

The FTC Eyeglass Rule mandates that prescribers provide patients with a copy of their eyeglass prescription immediately following an exam. This must be done automatically, whether or not the patient asks for it, and without levying any additional fees or requiring the purchase of ophthalmic goods.

Question 148: What sort of lens has a surface that is both convex and concave?

Biconvex
Meniscus (Correct answer)
Biconcave
Plano-convex

Correct answer: Meniscus

A meniscus lens is characterized by having one convex surface and one concave surface. This design allows for better optical performance, reduced peripheral aberrations, and a thinner, more aesthetically pleasing lens, especially for higher prescriptions. Most modern spectacle lenses are manufactured with a meniscus shape.

Question 149: Effective power is clinically important when converting between spectacle and contact lens prescriptions because:

Contact lenses have a different refractive index
Vertex distance changes alter the vergence power reaching the cornea (Correct answer)
Pupillary distance differs between the two modalities
Contact lenses always require stronger powers

Correct answer: Vertex distance changes alter the vergence power reaching the cornea

When vertex distance changes, the effective vergence at the cornea changes, requiring a power compensation for prescriptions above ±4.00 D.

Question 150: A state opticianry board can take disciplinary action against a licensee for all of the following EXCEPT:

Gross negligence in dispensing
Fraud or misrepresentation
Violations of state opticianry statutes
Charging fees the board considers too low (Correct answer)

Correct answer: Charging fees the board considers too low

Boards regulate professional conduct and competence; setting prices is a business decision not subject to disciplinary action by licensing boards.

Question 151: When adjusting a pure titanium or titanium alloy frame, what is a key characteristic the optician must account for?

It requires significant over-bending to retain the adjustment (Correct answer)
It can only be adjusted using specialized cold-bending pliers
It becomes very brittle when heated
It should never be heated above room temperature

Correct answer: It requires significant over-bending to retain the adjustment

Titanium is known for its strength, lightness, and flexibility, but it also has a high degree of 'springiness' or memory. This means the optician must often over-bend the frame past the desired point, allowing it to spring back into the correct alignment.

Question 152: When measuring pupillary distance (PD) for a patient with significant facial asymmetry, which method is most accurate?

Monocular PD from each eye to the nose bridge (Correct answer)
Distance PD minus 3mm for near
Binocular PD only
Average of three binocular measurements

Correct answer: Monocular PD from each eye to the nose bridge

Monocular PD measurements account for facial asymmetry by measuring each eye independently from the nose bridge.

Question 153: When solving for the cross-cylinder power used to refine cylinder axis and power, the examiner adds a lens whose:

Power equals half the estimated cylinder error
Axis aligns exactly with the suspected cylinder axis
Principal meridians are at 45° to the correcting cylinder axis (Correct answer)
Spherical power equals the working distance correction

Correct answer: Principal meridians are at 45° to the correcting cylinder axis

A Jackson Cross Cylinder (JCC) is placed with its principal meridians at 45° to the trial cylinder axis to test axis, then straddling it to test power.

Question 154: A patient completes their eye exam, pays for the service, and asks for a copy of their spectacle prescription to take with them. The office policy is to only release prescriptions to patients who purchase eyewear from the in-house optical. According to the FTC Eyeglass Rule, what is the legal obligation of the prescriber?

They can withhold the prescription until the patient agrees to look at their frame selection.
They are only required to release the prescription directly to another optical dispenser, not to the patient.
They can charge a reasonable fee for providing a paper copy of the prescription.
They must provide the patient with a copy of their prescription immediately after the exam, without requiring a purchase. (Correct answer)

Correct answer: They must provide the patient with a copy of their prescription immediately after the exam, without requiring a purchase.

The Federal Trade Commission (FTC) Eyeglass Rule requires prescribers to give patients their prescription immediately after an eye exam is complete. The rule prohibits conditioning the release of a prescription on the patient's agreement to purchase eyewear from the prescriber and forbids charging an additional fee for the prescription itself.

Question 155: What is the main advantage of Trivex over polycarbonate as an impact-resistant lens material?

Trivex has a higher Abbe value providing better optical clarity (Correct answer)
Trivex is available in a wider range of tints
Trivex is significantly less expensive
Trivex has a higher refractive index (1.74 vs 1.586)

Correct answer: Trivex has a higher Abbe value providing better optical clarity

Trivex has an Abbe value of approximately 45 compared to polycarbonate's 30, giving Trivex significantly better optical clarity and less chromatic aberration while maintaining excellent impact resistance.

Question 156: Which of the following tasks generally falls outside the legal scope of practice for a dispensing optician?

Performing a refraction to determine a patient's visual correction. (Correct answer)
Duplicating a pair of single vision lenses from the patient's current glasses.
Adjusting frames to modify pantoscopic tilt and face form.
Measuring a patient's pupillary distance and segment height.

Correct answer: Performing a refraction to determine a patient's visual correction.

A dispensing optician's role is to fit and dispense eyewear based on a valid prescription written by a licensed optometrist or ophthalmologist. Performing a refraction—the clinical process of using tests to determine a patient's refractive error and prescription—is the legal responsibility of an optometrist or ophthalmologist and is outside the optician's scope of practice.

Question 157: While verifying a PAL, you notice that the reticle is displaced vertically at the prism reference point (PRP), even when the lens is correctly oriented. This indicates the presence of:

A warped lens
Unwanted horizontal prism
An incorrect prescription
Prism-thinning (yoked prism) (Correct answer)

Correct answer: Prism-thinning (yoked prism)

Prism-thinning, also known as yoked or equalized prism, is vertical prism deliberately ground into a pair of PALs to reduce thickness differences between the top and bottom edges. It is measured at the prism reference point and should be equal in magnitude and direction for both lenses.

Question 158: What is the prismatic effect at a point 4 mm below the optical center of a -3.00 D lens?

0.75Δ base up
1.2Δ base down
1.2Δ base up (Correct answer)
0.75Δ base down

Correct answer: 1.2Δ base up

Using Prentice's Rule: P = d × F = 0.4 cm × 3.00 = 1.2Δ. For a minus lens, the prism base is toward the optical center (base up when point is below OC).

Question 159: Which layer of the retina contains the photoreceptor cells (rods and cones)?

Nerve fiber layer
Inner nuclear layer
Outer nuclear layer (Correct answer)
Ganglion cell layer

Correct answer: Outer nuclear layer

The outer nuclear layer contains the cell bodies of the photoreceptor cells, including rods and cones.

Question 160: When transposing a prescription from minus to plus cylinder form, the new sphere power will always be:

More plus than the original sphere
The same as the original sphere
More minus (or less plus) than the original sphere (Correct answer)
Equal to the original cylinder power

Correct answer: More minus (or less plus) than the original sphere

The new sphere is calculated by algebraically adding the original sphere and cylinder. Since you are starting with a minus cylinder, you will be adding a negative number to the sphere, which will always result in a new sphere power that is more minus (or less plus) than the original.

Question 161: The keratometer (ophthalmometer) measures which property of the cornea?

The intraocular pressure
The curvature (radius of curvature) of the central anterior corneal surface (Correct answer)
The thickness of the cornea
The axial length of the eye

Correct answer: The curvature (radius of curvature) of the central anterior corneal surface

The keratometer measures the radius of curvature of the anterior corneal surface at the central 3mm zone, used for contact lens base curve selection and detecting astigmatism.

Question 162: Which type of lens surface eliminates the tangential and sagittal focus errors simultaneously?

Atoric (Correct answer)
Spherical
Lenticular
Toric

Correct answer: Atoric

Atoric surfaces are designed to correct both tangential and sagittal oblique astigmatic errors simultaneously.

Question 163: What is the base curve of a lens?

The reference curve from which other curves are measured (Correct answer)
The curve of the back surface
The flattest curve on the front surface
The curve that determines the optical center

Correct answer: The reference curve from which other curves are measured

The base curve is the reference curve used to define the lens family. All other curves are measured relative to it.

Question 164: When measuring progressive addition lenses (PALs) with a lensometer, the distance power is measured:

Through the intermediate zone
At the geometric center of the lens
Through the distance zone in the upper portion (Correct answer)
Through the near zone

Correct answer: Through the distance zone in the upper portion

The distance power of a PAL is measured through the upper distance zone, where the prescribed distance Rx is located.

Question 165: The anterior chamber of the eye is the space between the:

Iris and ciliary body
Lens and vitreous
Retina and choroid
Cornea and iris/lens (Correct answer)

Correct answer: Cornea and iris/lens

The anterior chamber is bounded anteriorly by the corneal endothelium and posteriorly by the iris and anterior lens surface, filled with aqueous humor.

Question 166: According to ANSI Z80.1 standards, what is the tolerance for sphere power on a single vision lens with a power of +4.50 D?

2% of the power
+/- 0.06 D
+/- 0.13 D (Correct answer)
+/- 0.25 D

Correct answer: +/- 0.13 D

The ANSI Z80.1-2020 standard specifies a tolerance of +/- 0.13 D for sphere powers between 0.00 D and +/- 6.50 D. Since +4.50 D falls within this range, this is the applicable tolerance.

Question 167: A lens has a base curve of 6.00 D and a back curve of -4.00 D. What is the approximate refractive power of the lens?

+10.00 D
+4.00 D
-2.00 D
+2.00 D (Correct answer)

Correct answer: +2.00 D

Lens power ≈ front curve + back curve = +6.00 + (-4.00) = +2.00 D, using the lensmaker's principle for thin lenses.

Question 168: Which adjustment corrects a frame where one lens sits higher than the other when the patient wears it?

Tighten all hinge screws
Adjust the pantoscopic tilt symmetrically
Adjust the nose pad heights unequally to level the frame (Correct answer)
Reduce the temple spread

Correct answer: Adjust the nose pad heights unequally to level the frame

Uneven nose pad heights can compensate for facial asymmetry or unequal ear heights, leveling the frame in front of the patient's eyes.

Question 169: A lensometer target appears as two sets of lines oriented 90 degrees apart. The lines running in one direction clear at +2.00 and those running perpendicular clear at +3.50. What is the prescription?

+2.00 –1.50 × axis of blurred lines
+3.50 +1.50 × axis of second clear lines
+2.00 +1.50 × axis of first clear lines (Correct answer)
+3.50 –1.50 × axis of first clear lines

Correct answer: +2.00 +1.50 × axis of first clear lines

Starting with the lower power meridian (+2.00) as the sphere, the cylinder is the algebraic difference (+1.50), and the axis aligns with the first set of lines to clear.

Question 170: Which cells in the retina are responsible for color vision?

Rods
Cones (Correct answer)
Amacrine cells
Bipolar cells

Correct answer: Cones

Cone photoreceptors, concentrated in the fovea, are responsible for color vision and fine detail under photopic (bright light) conditions.

Question 171: Which instrument is used to measure the base curve of a finished spectacle lens?

Distometer
Geneva lens clock (lens gauge) (Correct answer)
Lensometer
Pupillometer

Correct answer: Geneva lens clock (lens gauge)

The Geneva lens clock (lens gauge) measures the surface curvature, allowing the base curve of a spectacle lens to be determined.

Question 172: Which lens treatment blocks wavelengths below approximately 380nm to protect against UV radiation?

Mirror coating
Anti-reflective coating
UV400 treatment (Correct answer)
Photochromic treatment

Correct answer: UV400 treatment

UV400 treatment blocks all ultraviolet light up to 400nm wavelength, providing comprehensive UV protection for the eye.

Question 173: Night blindness (nyctalopia) is most commonly associated with deficiency of which vitamin?

Vitamin D
Vitamin A (Correct answer)
Vitamin B12
Vitamin C

Correct answer: Vitamin A

Vitamin A is essential for the synthesis of rhodopsin in rod photoreceptors; its deficiency impairs dark adaptation and causes night blindness.

Question 174: What is the function of a scratch-resistant hard coat applied to plastic ophthalmic lenses?

Increases the refractive index of the lens material
Provides a more durable surface to resist surface abrasions (Correct answer)
Blocks UV radiation from reaching the eye
Changes tint density based on ambient light conditions

Correct answer: Provides a more durable surface to resist surface abrasions

Hard coats are thin, chemically bonded layers applied to plastic lenses to increase surface hardness and resistance to scratching, significantly extending the usable life of the lens.

Question 175: Which muscle of the iris constricts the pupil (miosis)?

Dilator pupillae
Ciliary muscle
Superior rectus
Sphincter pupillae (Correct answer)

Correct answer: Sphincter pupillae

The sphincter pupillae muscle, innervated by the parasympathetic nervous system via CN III, constricts the pupil.

Question 176: Photochromic lenses activate (darken) in response to:

Ultraviolet radiation (Correct answer)
Infrared radiation
Visible light only
Heat from sunlight

Correct answer: Ultraviolet radiation

Photochromic lenses darken when exposed to UV radiation, which triggers a chemical or structural change in the photochromic molecules.

Question 177: When viewing a near object, the visual axes of both eyes converge. This convergence is controlled primarily by which muscles?

Superior recti
Inferior obliques
Lateral recti
Medial recti (Correct answer)

Correct answer: Medial recti

Both medial rectus muscles adduct the eyes simultaneously to produce convergence during near fixation.

Question 178: What frame adjustment lowers the frame's front?

Bringing the pads closer together
Bending the pad arms down
Spreading pads further apart (Correct answer)
More pantoscopic tilt

Correct answer: Spreading pads further apart

Spreading the nose pads further apart on a frame causes the frame front to sit lower on the wearer's face. This adjustment effectively increases the distance between the pads, allowing the frame to slide down the bridge of the nose. Conversely, bringing the pads closer together would raise the frame front.

Question 179: Which statement about plano (non-prescription) sunglasses is accurate under FDA regulations?

They are regulated as Class III medical devices
They must meet the same impact resistance standard as prescription lenses (Correct answer)
They only need to comply with ANSI Z80.3 UV protection standards
They are unregulated consumer products with no safety requirements

Correct answer: They must meet the same impact resistance standard as prescription lenses

The FDA requires that non-prescription sunglasses meet the same drop ball impact resistance test as prescription dress lenses.

Question 180: A bifocal add creates a prismatic effect at the reading level. For a +2.50 add with the reading zone 8 mm below the optical center, what is the prismatic effect using Prentice's Rule?

2.0Δ base-up (Correct answer)
20Δ base-up
2.0Δ base-down
0.2Δ base-down

Correct answer: 2.0Δ base-up

Δ = D × c = 2.50 × 0.8 cm = 2.0Δ; a plus lens below its optical center produces base-up prism.

Question 181: A progressive addition lens (PAL) is ordered with a +2.00 add. What is the purpose of the 'corridor' in a PAL?

To create a gradual transition zone between distance and near powers (Correct answer)
To provide the distance prescription zone
To increase the width of the reading area
To reduce peripheral distortion

Correct answer: To create a gradual transition zone between distance and near powers

The corridor in a PAL is the progressive zone through which power gradually increases from the distance prescription to the full near addition power.

Question 182: What does 'specific gravity' indicate when comparing lens materials?

The refractive index at the sodium D line
How much the material disperses light
The material's weight relative to an equal volume of water (Correct answer)
The material's scratch resistance rating

Correct answer: The material's weight relative to an equal volume of water

Specific gravity is the ratio of a material's density to that of water; lower specific gravity means a lighter lens.

Question 183: A patient presents with symptoms including distorted vision where straight lines appear wavy, ghost images, and rapidly changing myopic and astigmatic refractive error. These are classic signs of which corneal condition?

Keratoconus (Correct answer)
Macular Degeneration
Conjunctivitis
Cataract

Correct answer: Keratoconus

Keratoconus is a progressive eye disease in which the normally round cornea thins and begins to bulge into a cone-like shape. This cone shape deflects light as it enters the eye on its way to the light-sensitive retina, causing distorted vision.

Question 184: Bowman's layer is located between which two corneal layers?

Epithelium and stroma (Correct answer)
Endothelium and Descemet's membrane
Stroma and Descemet's membrane
Epithelium and endothelium

Correct answer: Epithelium and stroma

Bowman's layer is an acellular condensation of stromal collagen immediately beneath the corneal epithelium.

Question 185: A lens has a power of +2.50 D. What is its focal length in meters?

0.25 m
2.50 m
0.40 m (Correct answer)
0.50 m

Correct answer: 0.40 m

Focal length = 1 / Power, so 1 / 2.50 = 0.40 meters.

Question 186: A metal frame sits too low on the patient's nose. The optician should:

Increase pantoscopic tilt
Narrow the temple spread
Increase the splay angle of the nose pads (open them outward) (Correct answer)
Decrease the splay angle of the nose pads

Correct answer: Increase the splay angle of the nose pads (open them outward)

Opening the nose pads outward (increasing splay) raises the frame by changing the pad contact position on the nose.

Question 187: A patient's right eye requires 1.50Δ base in. The lens power is +3.00 D. In which direction and how far should the optical center be decentered?

5 mm temporally
5 mm nasally (Correct answer)
0.5 mm temporally
0.5 mm nasally

Correct answer: 5 mm nasally

d = 1.50/3.00 = 0.5 cm = 5 mm; for a plus lens, decentering the OC nasally places the eye temporal to the OC, inducing base-in prism.

Question 188: A state law requires opticians to hold an associate degree for licensure. A federal law requires only a high school diploma and passing a national exam. Which applies?

The FTC, which arbitrates between state and federal rules
Federal law, because it supersedes state requirements
State law, because states can set higher minimums (Correct answer)
Neither; the ABO sets all licensing requirements

Correct answer: State law, because states can set higher minimums

States have the authority to set professional licensing requirements higher than any federal minimum, so the stricter state standard would apply.

Question 189: Which temple style provides the most secure fit for an active patient?

Cable (riding bow) temple (Correct answer)
Convertible temple
Skull temple
Library (straight) temple

Correct answer: Cable (riding bow) temple

Cable temples wrap around the ear and provide the most secure fit, making them ideal for active patients or children.

Question 190: A patient's complaint is that one lens appears higher than the other when looking at their glasses from the front. This is most likely caused by:

Incorrect PD measurement
Facial asymmetry or uneven temple height (Correct answer)
Unequal lens powers
Wrong anti-reflective coating

Correct answer: Facial asymmetry or uneven temple height

Uneven lens height appearance is typically caused by facial asymmetry or temples adjusted to different heights, not the lens powers themselves.

Question 191: The FTC's Contact Lens Rule requires sellers to verify a contact lens prescription before dispensing. A seller may dispense without verification if the prescriber:

Has not responded to a single fax within 48 hours
Has not responded within 8 business hours (Correct answer)
Fails to respond within 1 business day
Cannot be reached by any means

Correct answer: Has not responded within 8 business hours

Under the Contact Lens Rule, if a prescriber does not respond to a verification request within 8 business hours, the seller may treat the prescription as verified (passive verification).

Question 192: Which lens treatment provides the greatest blockage of UV radiation?

80% gray tint on CR-39
Photochromic lenses in their darkened (activated) state (Correct answer)
Untreated CR-39
Clear polycarbonate with AR coat only

Correct answer: Photochromic lenses in their darkened (activated) state

Fully activated photochromic lenses block essentially 100% of UVA and UVB radiation.

Question 193: According to Prentice's Rule, a lens of +2.00 D with the optical center decentered 5 mm will produce how many prism diopters?

10.0 Δ
2.5 Δ
1.0 Δ (Correct answer)
0.5 Δ

Correct answer: 1.0 Δ

Prentice's Rule: Prism (Δ) = Power (D) × Decentration (cm) = 2.00 × 0.5 cm = 1.0 Δ.

Question 194: What ANSI standard governs prescription ophthalmic lenses in the United States?

ANSI Z80.5
ANSI Z80.1 (Correct answer)
ANSI Z80.3
ANSI Z87.1

Correct answer: ANSI Z80.1

ANSI Z80.1 sets the tolerances and requirements for prescription ophthalmic lenses dispensed in the United States.

Question 195: Transpose the prescription Plano +2.50 x 030 into minus cylinder form.

+2.50 -2.50 x 120 (Correct answer)
-2.50 +2.50 x 120
Plano -2.50 x 120
+2.50 +2.50 x 120

Correct answer: +2.50 -2.50 x 120

Start with the sphere (0.00) and add the cylinder (+2.50) to get the new sphere: +2.50. Change the cylinder sign to minus: -2.50. Change the axis by 90 degrees: 30 + 90 = 120. The result is +2.50 -2.50 x 120.

Question 196: When performing hand neutralization of an unknown lens and the image moves 'against' (opposite to lens movement), the lens is:

Minus (concave)
A prism
Plus (convex) (Correct answer)
Plano

Correct answer: Plus (convex)

A plus (convex) lens produces 'against' movement (the image moves opposite to the direction of lens movement) during hand neutralization.

Question 197: When verifying progressive lenses with a lensometer, which zone should be used to verify the cylinder power and axis?

The near reference point
The corridor midpoint
The intermediate zone
The distance reference point (DRP) (Correct answer)

Correct answer: The distance reference point (DRP)

Cylinder power and axis are verified at the distance reference point (DRP) because the distance zone contains the full prescribed cylinder.

Question 198: If a patient's contact lens prescription has expired, under the FTCLCA, a seller:

May dispense if the patient signs a liability waiver
May dispense up to a 30-day supply under an emergency exception
May not dispense lenses and must refer the patient for a new exam (Correct answer)
May dispense a 90-day supply as a professional courtesy

Correct answer: May not dispense lenses and must refer the patient for a new exam

Under the FTCLCA and FTC Contact Lens Rule, sellers may not dispense contact lenses on an expired prescription; the patient must obtain a new examination and valid prescription.

Question 199: Which characteristic of a sunglass lens is described by the term 'luminous transmittance'?

The ability of the lens to reduce glare
The percentage of visible light that passes through the lens (Correct answer)
The percentage of UV light blocked by the lens
The warmth of the lens tint color

Correct answer: The percentage of visible light that passes through the lens

Luminous transmittance is the ratio of the luminous flux transmitted through a lens to the incident luminous flux — essentially what percentage of visible light passes through.

Question 200: Which layer of the cornea is responsible for rapid regeneration after injury?

Epithelium (Correct answer)
Bowman's layer
Descemet's membrane
Stroma

Correct answer: Epithelium

The corneal epithelium can regenerate completely within 24–48 hours due to its high cell turnover rate.

Question 201: Which lens treatment is specifically designed to filter high-energy visible (HEV) blue light in the 380–500 nm range?

Anti-reflective coating
Blue light blocking coating (Correct answer)
Photochromic treatment
Polarized filter

Correct answer: Blue light blocking coating

Blue light blocking coatings selectively filter or reflect high-energy visible light in the 380–500 nm range, which is associated with digital eye strain and discussed as a factor in potential retinal stress.

Question 202: What is the primary function of the choroid layer?

Produce aqueous humor
Control lens shape
Provide nutrient supply to the outer retina (Correct answer)
Regulate intraocular pressure

Correct answer: Provide nutrient supply to the outer retina

The choroid is a highly vascular layer that provides oxygen and nutrients to the outer retinal layers, including the photoreceptors.

ABO NOCE Basic Opticianry Exam

The ABO NOCE Basic Opticianry Exam exam validates essential knowledge and skills required for certification or licensure in this field.

200

Questions

150 min

Time Limit

70%

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