ABO NOCE Basic Opticianry Trivia 3 — Questions and Answers
Question 1: What is the primary function of an anti-reflective (AR) coating on eyeglass lenses?
- To increase lens durability against scratches
- To reduce surface reflections and improve light transmission (Correct answer)
- To block all ultraviolet radiation
- To darken the lens in sunlight
Correct answer: To reduce surface reflections and improve light transmission
AR coatings reduce surface reflections through destructive interference, increasing light transmission and reducing glare for the wearer.
Question 2: What does 'OD' stand for in an eyeglass prescription?
- Oculus Dexter (right eye) (Correct answer)
- Oculus Dominans (dominant eye)
- Optical Density
- Outer Diameter
Correct answer: Oculus Dexter (right eye)
OD is the Latin abbreviation for 'Oculus Dexter,' meaning the right eye, used universally in ophthalmic prescriptions.
Question 3: Which prism direction is used to treat an esophoria (tendency for eyes to turn inward)?
- Base-in prism
- Base-out prism (Correct answer)
- Base-up prism
- Base-down prism
Correct answer: Base-out prism
Base-out prism is prescribed for esophoria because it shifts the image outward, reducing the inward convergence demand on the eyes.
Question 4: What is the term for the smallest detail a lens system can distinguish, often expressed as cycles per degree?
- Depth of focus
- Resolving power (Correct answer)
- Chromatic aberration
- Spherical aberration
Correct answer: Resolving power
Resolving power (or spatial resolution) describes the ability of an optical system to distinguish fine detail, commonly expressed in cycles per degree.
Question 5: A frame with a DBL (distance between lenses) of 18 mm and lens size of 52 mm has what frame PD?
- 52 mm
- 70 mm (Correct answer)
- 34 mm
- 88 mm
Correct answer: 70 mm
Frame PD = lens size + DBL = 52 + 18 = 70 mm; this represents the horizontal width across both lenses.
Question 6: What type of lens has a gradual change in power from distance to near with no visible dividing line?
- Bifocal
- Trifocal
- Progressive addition lens (PAL) (Correct answer)
- Flat-top bifocal
Correct answer: Progressive addition lens (PAL)
Progressive addition lenses (PALs) provide a seamless gradient from distance to intermediate to near power without a visible segment line.
Question 7: What is the recommended minimum prescription power at which vertex distance compensation becomes clinically significant?
- ±2.00 D
- ±3.00 D
- ±4.00 D
- ±5.00 D (Correct answer)
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.
ABO NOCE Basic Opticianry Trivia 3
What is the primary function of an anti-reflective (AR) coating on eyeglass lenses?