CPOA Spectacle Dispensing 4

Question 1

Prentice's Rule states that prismatic effect (prism diopters) equals:

Accepted Answer

Lens power multiplied by decentration in cm

Answer

Prentice's Rule: Δ = F × c, where F is lens power in diopters and c is decentration in centimeters.

Question 2

A patient picking up new glasses complains the left lens looks darker than the right. Which is the most likely explanation for plastic frames?

Accepted Answer

The tinting process was uneven or the lenses were different materials

Answer

Uneven tint absorption typically results from inconsistent immersion time, temperature, or different lens materials that take dye differently.

Question 3

Which temple style wraps completely around the ear and is commonly used in children's or safety frames?

Accepted Answer

Riding bow (cable) temple

Answer

Riding bow (cable) temples curl completely around the ear, providing extra retention used in active-wear, safety, and pediatric frames.

Question 4

The minimum recommended lens size for a given prescription is determined primarily by:

Accepted Answer

The patient's pupillary distance and frame PD

Answer

The minimum blank size must accommodate the optical center placement relative to the patient's PD and the frame's geometric center PD.

Question 5

Which coating is applied to a lens to reduce the build-up of static charge and repel dust particles?

Accepted Answer

Anti-static coating

Answer

Anti-static coatings neutralize electrostatic charges on the lens surface, helping prevent dust and lint attraction.

(CPOA) Certified Paraoptometric Assistant Practice Test