CPOT CPOT Optical Dispensing & Lens Technology

Question 1

Which lens material has the highest Abbe value, indicating the least chromatic aberration?

Accepted Answer

CR-39 plastic

Answer

Polycarbonate

Answer

Trivex

Answer

High-index 1.74

Question 2

A lens prescription written as -2.00 -1.50 × 090 indicates:

Accepted Answer

Myopia with astigmatism, axis at 90 degrees

Answer

Hyperopia with no astigmatism

Answer

Hyperopia with astigmatism, axis at 180 degrees

Answer

Emmetropia with astigmatism

Question 3

Pupillary distance (PD) is measured to ensure that the optical centers of the lenses align with the:

Accepted Answer

Center of each pupil

Answer

Outer canthi of each eye

Answer

Inner canthi of each eye

Answer

Center of each iris

Question 4

Antireflective (AR) coating on ophthalmic lenses primarily works by:

Accepted Answer

Using thin-film interference to cancel reflected light

Answer

Hardening the lens surface

Answer

Absorbing UV radiation

Answer

Tinting the lens to reduce glare

Question 5

Which type of lens is recommended for patients who need correction for distance, intermediate, and near vision in a single lens without visible lines?

Accepted Answer

Progressive addition lens (PAL)

Answer

Bifocal

Answer

Trifocal

Answer

Single vision lens

Question 6

The base curve of an ophthalmic lens is defined as:

Accepted Answer

The reference curve from which other lens curves are calculated

Answer

The total power of the lens

Answer

The curvature of the back surface

Answer

The thickness at the lens edge