ABO ADVANCED CERTIFICATION
FINAL EXAM QUESTIONS AND
ANSWERS 100% VERIFIED. JUST
RELEASED
1. A lens has a prescription of -4.00 -2.00 x 090. What is the power of the lens in the 180-
degree meridian?
A. -4.00 D
B. Plano
C. -2.00 D
D. -6.00 D
Answer: D
Conceptual Explanation: In minus cylinder form, the sphere power (-4.00) is at the axis
(090). The total power (-4.00 + -2.00 = -6.00) is 90 degrees away from the axis, which is the
180-degree meridian.
2. Using Prentice’s Rule, how much prism is induced if a patient is looking 5mm below the
optical center of a +4.00 D lens?
A. 0.2 prism diopters
B. 2.0 prism diopters Base Up
,C. 2.0 prism diopters Base Down
D. 20 prism diopters
Answer: B
Conceptual Explanation: Prentice’s Rule: P = c x D (where c is in cm). 0.5 cm x 4.00 D = 2.0
prism diopters. For a plus lens, looking below the optical center induces Base Up prism.
3. Which lens material has the highest Abbe value, indicating the least amount of chromatic
aberration?
A. Polycarbonate
B. High Index 1.67
C. CR-39 Plastic
D. Crown Glass
Answer: D
Conceptual Explanation: Crown Glass has an Abbe value of approximately 58-59, the
highest among common ophthalmic materials, resulting in minimal chromatic aberration.
4. A patient’s Rx is +2.00 -1.00 x 180. What is the equivalent sphere?
A. +1.00 D
B. +1.50 D
C. +2.50 D
, D. +0.50 D
Answer: B
Conceptual Explanation: Equivalent sphere is calculated by adding half of the cylinder
power to the sphere power. +2.00 + (-1.) = +2.00 - 0.50 = +1.50 D.
5. If the frame’s A measurement is 50mm and the DBL is 20mm, what is the Frame PD (GCD)?
A. 60mm
B. 70mm
C. 75mm
D. 65mm
Answer: B
Conceptual Explanation: Frame PD or Geometric Center Distance (GCD) is calculated as A
+ DBL. 50mm + 20mm = 70mm.
6. A lens clock calibrated for n=1.53 measures a surface as +6.00 D. If the lens is actually made
of Polycarbonate (n=1.586), what is the actual surface power?
A. +6.63 D
B. +5.43 D
C. +6.00 D
D. +7.12 D
FINAL EXAM QUESTIONS AND
ANSWERS 100% VERIFIED. JUST
RELEASED
1. A lens has a prescription of -4.00 -2.00 x 090. What is the power of the lens in the 180-
degree meridian?
A. -4.00 D
B. Plano
C. -2.00 D
D. -6.00 D
Answer: D
Conceptual Explanation: In minus cylinder form, the sphere power (-4.00) is at the axis
(090). The total power (-4.00 + -2.00 = -6.00) is 90 degrees away from the axis, which is the
180-degree meridian.
2. Using Prentice’s Rule, how much prism is induced if a patient is looking 5mm below the
optical center of a +4.00 D lens?
A. 0.2 prism diopters
B. 2.0 prism diopters Base Up
,C. 2.0 prism diopters Base Down
D. 20 prism diopters
Answer: B
Conceptual Explanation: Prentice’s Rule: P = c x D (where c is in cm). 0.5 cm x 4.00 D = 2.0
prism diopters. For a plus lens, looking below the optical center induces Base Up prism.
3. Which lens material has the highest Abbe value, indicating the least amount of chromatic
aberration?
A. Polycarbonate
B. High Index 1.67
C. CR-39 Plastic
D. Crown Glass
Answer: D
Conceptual Explanation: Crown Glass has an Abbe value of approximately 58-59, the
highest among common ophthalmic materials, resulting in minimal chromatic aberration.
4. A patient’s Rx is +2.00 -1.00 x 180. What is the equivalent sphere?
A. +1.00 D
B. +1.50 D
C. +2.50 D
, D. +0.50 D
Answer: B
Conceptual Explanation: Equivalent sphere is calculated by adding half of the cylinder
power to the sphere power. +2.00 + (-1.) = +2.00 - 0.50 = +1.50 D.
5. If the frame’s A measurement is 50mm and the DBL is 20mm, what is the Frame PD (GCD)?
A. 60mm
B. 70mm
C. 75mm
D. 65mm
Answer: B
Conceptual Explanation: Frame PD or Geometric Center Distance (GCD) is calculated as A
+ DBL. 50mm + 20mm = 70mm.
6. A lens clock calibrated for n=1.53 measures a surface as +6.00 D. If the lens is actually made
of Polycarbonate (n=1.586), what is the actual surface power?
A. +6.63 D
B. +5.43 D
C. +6.00 D
D. +7.12 D
