California Optician Licensing Practice
Exam Questions And Correct Answers
(Verified Answers) Plus Rationales 2025
Q&A | Instant Download Pdf
1. What is the standard base curve for a single vision lens with a +2.00D
prescription?
A. +2.00D
B. +6.00D
C. +0.50D
D. +3.00D
The base curve is typically +6.00D for standard single vision and most
lens types to ensure optical clarity and cosmetic appearance.
2. Which ANSI standard relates to prescription lens tolerances?
A. ANSI Z80.20
B. ANSI Z80.1
C. ANSI Z87.1
D. ANSI Z136.1
ANSI Z80.1 specifies tolerances for prescription ophthalmic lenses
including sphere, cylinder, and axis tolerances.
3. What type of lens design is most appropriate for a patient with
presbyopia?
, A. Single vision
B. Plano lens
C. Myodisc
D. Progressive addition lens
Progressive addition lenses are designed for presbyopic patients to
provide seamless vision at all distances.
4. What measurement is used to determine the vertical placement of
progressive lenses?
A. Pupillary distance
B. Seg height
C. Base curve
D. Cylinder axis
Segment height determines the vertical starting point for near vision
in progressive lenses.
5. Which tool is used to verify the curvature of a lens surface?
A. PD ruler
B. Lens clock
C. Caliper
D. Geneva lens measure
A lens clock measures the curvature (in diopters) of a lens surface to
check base curve or power.
6. Which material is the most impact-resistant for ophthalmic lenses?
A. Crown glass
B. CR-39
C. Polycarbonate
D. High-index plastic
Polycarbonate is highly impact-resistant and is the standard material
for children's eyewear and safety glasses.
, 7. What is the index of refraction for CR-39 plastic lenses?
A. 1.60
B. 1.498
C. 1.67
D. 1.74
CR-39 has a refractive index of 1.498, which affects lens thickness
and weight.
8. If a lens has a prescription of +3.00D and the optical center is
decentered 5 mm, what is the prism induced?
A. 0.5Δ
B. 1.5Δ
C. 2.5Δ
D. 3.5Δ
Prentice’s Rule: Prism = (Power × Decentration in cm). Here, 3 × 0.5 =
1.5Δ.
9. Which frame type requires a lens with a groove for secure mounting?
A. Full-rim
B. Metal frame
C. Rimless
D. Nylon frame
Rimless and semi-rimless (nylon) frames require grooved lenses to
hold them in place securely.
10. What is the allowable ANSI tolerance for horizontal prism
imbalance?
A. ±0.25Δ
B. ±0.50Δ
C. ±0.67Δ
D. ±1.00Δ
Exam Questions And Correct Answers
(Verified Answers) Plus Rationales 2025
Q&A | Instant Download Pdf
1. What is the standard base curve for a single vision lens with a +2.00D
prescription?
A. +2.00D
B. +6.00D
C. +0.50D
D. +3.00D
The base curve is typically +6.00D for standard single vision and most
lens types to ensure optical clarity and cosmetic appearance.
2. Which ANSI standard relates to prescription lens tolerances?
A. ANSI Z80.20
B. ANSI Z80.1
C. ANSI Z87.1
D. ANSI Z136.1
ANSI Z80.1 specifies tolerances for prescription ophthalmic lenses
including sphere, cylinder, and axis tolerances.
3. What type of lens design is most appropriate for a patient with
presbyopia?
, A. Single vision
B. Plano lens
C. Myodisc
D. Progressive addition lens
Progressive addition lenses are designed for presbyopic patients to
provide seamless vision at all distances.
4. What measurement is used to determine the vertical placement of
progressive lenses?
A. Pupillary distance
B. Seg height
C. Base curve
D. Cylinder axis
Segment height determines the vertical starting point for near vision
in progressive lenses.
5. Which tool is used to verify the curvature of a lens surface?
A. PD ruler
B. Lens clock
C. Caliper
D. Geneva lens measure
A lens clock measures the curvature (in diopters) of a lens surface to
check base curve or power.
6. Which material is the most impact-resistant for ophthalmic lenses?
A. Crown glass
B. CR-39
C. Polycarbonate
D. High-index plastic
Polycarbonate is highly impact-resistant and is the standard material
for children's eyewear and safety glasses.
, 7. What is the index of refraction for CR-39 plastic lenses?
A. 1.60
B. 1.498
C. 1.67
D. 1.74
CR-39 has a refractive index of 1.498, which affects lens thickness
and weight.
8. If a lens has a prescription of +3.00D and the optical center is
decentered 5 mm, what is the prism induced?
A. 0.5Δ
B. 1.5Δ
C. 2.5Δ
D. 3.5Δ
Prentice’s Rule: Prism = (Power × Decentration in cm). Here, 3 × 0.5 =
1.5Δ.
9. Which frame type requires a lens with a groove for secure mounting?
A. Full-rim
B. Metal frame
C. Rimless
D. Nylon frame
Rimless and semi-rimless (nylon) frames require grooved lenses to
hold them in place securely.
10. What is the allowable ANSI tolerance for horizontal prism
imbalance?
A. ±0.25Δ
B. ±0.50Δ
C. ±0.67Δ
D. ±1.00Δ
