Mixed Deck — All ABO NOCE Basic Opticianry Topics Flashcards
100 cards from real ABO NOCE Basic Opticianry practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 20 Mixed Deck — All ABO NOCE Basic Opticianry Topics flashcards as text
Which ANSI standard specifically addresses the requirements for prescription ophthalmic lenses?
Answer: ANSI Z80.1
ANSI Z80.1 covers the requirements and tolerances for prescription ophthalmic lenses dispensed in the United States.
When a patient reports that glasses feel tight on one side of the head only, the optician should first check:
Answer: The facial symmetry and temple alignment
Unilateral tightness often results from unequal temple spread or the patient's facial asymmetry requiring one temple to be adjusted differently.
Oblique astigmatism occurs when light rays pass through a lens at an angle. At what lens zone is this aberration most problematic?
Answer: Peripheral zone
Oblique astigmatism is a peripheral aberration that worsens as the angle of incidence increases away from the optical center.
A patient requests a frame with a very small B measurement. Which lens type will be most problematic to fit in this frame?
Answer: Progressive addition lens
Progressive addition lenses require adequate B measurement (vertical height) to accommodate the full progressive corridor from distance to near.
In a toric lens, the two principal meridians are always:
Answer: Perpendicular to each other
A toric surface has two principal meridians of maximum and minimum curvature that are always 90° apart.
A patient's prescription is OD: -5.00 D sphere, OS: -2.00 D sphere. If their pupils are decentered 4 mm inwards from the optical centers of the lenses, what is the total amount and direction of induced horizontal prism?
Answer: 2.8 prism diopters Base Out
Prentice's Rule (Prism = Power x Decentration in cm) is used for each eye. OD: 5.00 D x 0.4 cm = 2.0 p.d. For a minus lens, decentering IN induces Base OUT prism. OS: 2.00 D x 0.4 cm = 0.8 p.d. For a minus lens, decentering IN induces Base OUT prism. Since both eyes induce Base Out prism, the effects are additive: 2.0 p.d. BO + 0.8 p.d. BO = 2.8 p.d. Base Out total.
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?
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.
Which of the following correctly describes the spherical equivalent?
Answer: Sphere plus half the cylinder
Spherical equivalent = sphere + (cylinder ÷ 2), used to approximate a spherocylindrical lens as a single sphere.
For a lens with a sphere power of +8.00 D, what is the ANSI Z80.1 tolerance for power?
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.
What sort of lens has a surface that is both convex and concave?
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.
The sclera transitions to the cornea at a boundary zone known as the:
Answer: Limbus
The limbus is the transitional zone between the opaque sclera and transparent cornea and also contains stem cells for corneal regeneration.
When a patient looks 30 degrees to the right through their spectacle lens, the effective power they experience differs from the labeled prescription due to:
Answer: Off-axis aberrations, primarily oblique astigmatism
Off-axis gaze subjects rays to oblique incidence, introducing oblique astigmatism that changes the effective power experienced by the wearer.
Horner's syndrome affecting the eye includes miosis, ptosis, and which other sign?
Answer: Anhidrosis of the ipsilateral face
Disruption of the sympathetic pathway causes the classic triad: miosis, ptosis, and anhidrosis on the same side.
When using a focimeter (lensometer) to verify a lens power of -3.00 -1.25 × 090, which set of lines do you focus first?
Answer: The lines running at 180° (the sphere meridian)
By convention, you first focus the lines running parallel to the cylinder axis to find the sphere power, then rotate to find the cylinder power.
When a dispensary employee is exposed to a communicable disease through a patient encounter, which regulatory framework primarily governs the employer's obligations?
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.
An infrared (IR) thermometer is sometimes used in optical dispensing to:
Answer: Verify the temperature of a frame warmer to prevent overheating frames
IR thermometers help opticians monitor frame heater temperatures so plastic frames are not overheated, which can cause warping, discoloration, or bubbling.
A scratch-resistant coating on a plastic lens primarily adds hardness by:
Answer: Depositing a thin layer of silica-based compound
Scratch-resistant (hard) coatings use silica-based or similar inorganic compounds applied in thin layers to harden the plastic surface.
Proliferative diabetic retinopathy differs from non-proliferative diabetic retinopathy by the presence of:
Answer: New blood vessel formation
The defining feature of proliferative diabetic retinopathy is neovascularization — growth of fragile new vessels on the retina or optic disc.
When neutralizing a lens with a lensometer, a spherical lens is confirmed when:
Answer: Both lines of the target are clear simultaneously at the same drum reading
A pure sphere shows both target lines simultaneously in sharp focus at one drum reading, confirming no cylinder power.
Transpose -4.00 +2.00 x 075. What is the complete transposed prescription?
Answer: -2.00 -2.00 x 165
New sphere = -4.00 + 2.00 = -2.00; new cyl = -2.00; new axis = 075 + 90 = 165.