ABO NOCE Basic Opticianry ANSI Z80.1 Standards and Tolerances 2 — Questions and Answers
Question 1: According to ANSI Z80.1, what is the power tolerance for a single-vision lens with a prescribed sphere power of -6.00 D?
- ±0.06 D
- ±0.12 D (Correct answer)
- ±0.13 D
- ±0.18 D
Correct answer: ±0.12 D
For lenses with a vertex power greater than 6.50 D, the tolerance is ±2% of the prescribed power, but for -6.00 D the standard ±0.12 D tolerance applies.
Question 2: What is the ANSI Z80.1 tolerance for cylinder axis when the cylinder power is between 0.75 D and 1.50 D?
- ±2 degrees
- ±3 degrees (Correct answer)
- ±5 degrees
- ±7 degrees
Correct answer: ±3 degrees
ANSI Z80.1 specifies ±3 degrees of axis tolerance when the cylinder power falls between 0.75 D and 1.50 D.
Question 3: Under ANSI Z80.1, what is the maximum allowable unwanted prism for a lens with a prescribed power of -2.00 D sphere at the distance reference point?
- 0.25Δ
- 0.33Δ (Correct answer)
- 0.50Δ
- 1.00Δ
Correct answer: 0.33Δ
ANSI Z80.1 allows a maximum of 0.33Δ of unwanted prism at the distance reference point for lenses up to ±3.37 D.
Question 4: Which ANSI Z80.1 standard governs prescription ophthalmic lenses?
- ANSI Z80.1-2015 (Correct answer)
- ANSI Z80.3-2015
- ANSI Z80.9-2020
- ANSI Z87.1-2015
Correct answer: ANSI Z80.1-2015
ANSI Z80.1 specifically covers prescription ophthalmic lenses, including tolerances for power, prism, and optical quality.
Question 5: What is the ANSI Z80.1 tolerance for the add power of a progressive addition lens?
- ±0.06 D
- ±0.12 D (Correct answer)
- ±0.14 D
- ±0.25 D
Correct answer: ±0.12 D
ANSI Z80.1 specifies ±0.12 D tolerance for the add power of progressive addition lenses.
Question 6: According to ANSI Z80.1, what is the cylinder axis tolerance when prescribed cylinder power is greater than 1.50 D?
- ±1 degree
- ±2 degrees (Correct answer)
- ±3 degrees
- ±5 degrees
Correct answer: ±2 degrees
For cylinder powers exceeding 1.50 D, ANSI Z80.1 tightens the axis tolerance to ±2 degrees.
Question 7: Under ANSI Z80.1, the minimum lens thickness for impact-resistant lenses made of glass should be no less than:
- 1.0 mm at the thinnest point
- 2.0 mm at the thinnest point (Correct answer)
- 2.5 mm at the center
- 3.0 mm at the center
Correct answer: 2.0 mm at the thinnest point
ANSI Z80.1 requires glass dress ophthalmic lenses to be a minimum of 2.0 mm thick at the thinnest point for impact resistance.
ABO NOCE Basic Opticianry ANSI Z80.1 Standards and Tolerances 2
According to ANSI Z80.1, what is the power tolerance for a single-vision lens with a prescribed sphere power of -6.00 D?