ABO NOCE Basic Opticianry Trivia 5 — Questions and Answers
Question 1: What is the Prentice Rule formula used to calculate prism in opticianry?
- Prism (Δ) = Power (D) × Decentration (cm) (Correct answer)
- Prism (Δ) = Power (D) / Decentration (mm)
- Prism (Δ) = Decentration (cm) / Power (D)
- Prism (Δ) = Power (D) + Decentration (cm)
Correct answer: Prism (Δ) = Power (D) × Decentration (cm)
Prentice's Rule states that prism (in prism diopters) equals the lens power (in diopters) multiplied by the decentration (in centimeters).
Question 2: Which segment style bifocal provides the widest near reading area?
- Executive (E-style) bifocal (Correct answer)
- Flat-top 28 bifocal
- Round 22 bifocal
- Blended bifocal
Correct answer: Executive (E-style) bifocal
The Executive (E-style or Franklin-style) bifocal has a full-width segment that spans the entire lens width, providing the widest near zone.
Question 3: What does 'photochromic' mean in the context of ophthalmic lenses?
- The lens changes color permanently after UV exposure
- The lens darkens in UV light and clears indoors (Correct answer)
- The lens reflects polarized light
- The lens has a mirror-like surface coating
Correct answer: The lens darkens in UV light and clears indoors
Photochromic lenses contain molecules that reversibly darken when exposed to UV radiation and return to a clear state when UV is removed indoors.
Question 4: In the ANSI Z80.1 standard, what is the tolerance for sphere power for a lens with a power of -4.00 D?
- ±0.06 D
- ±0.12 D (Correct answer)
- ±0.13 D
- ±0.25 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 5: A patient's near PD is 62 mm and distance PD is 66 mm. What is each eye's near monocular PD if the eyes converge symmetrically?
- 32 mm each
- 31 mm each (Correct answer)
- 33 mm each
- 30 mm each
Correct answer: 31 mm each
Near PD of 62 mm divided by 2 equals 31 mm per eye, representing symmetric convergence from distance to near.
Question 6: What material property describes a lens's resistance to impact, critical for safety eyewear standards?
- Refractive index
- Abbe value
- Impact resistance (Correct answer)
- Specific gravity
Correct answer: Impact resistance
Impact resistance describes a lens material's ability to absorb and withstand sudden force without fracturing, which is essential for safety eyewear compliance (ANSI Z87.1).
Question 7: What is the term for the angle formed between the front plane of a frame and the plane of the lens, viewed from above?
- Pantoscopic tilt
- Face form angle (Correct answer)
- Retroscopic tilt
- Wrap angle
Correct answer: Face form angle
The face form angle (also called face-form wrap) is the horizontal curvature of the frame as viewed from above, affecting how the lens wraps around the face.
ABO NOCE Basic Opticianry Trivia 5
What is the Prentice Rule formula used to calculate prism in opticianry?