Unit 3 - Tints, Coatings, & Special Lens Designs

Question 1

A polarized lens would be beneficial for which of the following activities?

a. basketball
b. tennis
c. boating
d. gymnastics

Answer 1

b. boating

Question 2

An on-camera TV personality would find which of the following lens choices most beneficial?

a. UV treatment
b. scratch coating
c. absorptive tint
d. A/R coating

Answer 2

d. AR coating

Question 3

Which of the following may reduce the risk of cataracts?

a. scratch resistant coating
b. AR coating
c. UV coating
d. hydrophobic coating

Answer 3

c. UV coating

Question 4

A hydrophobic top coating is now being added to most AR coatings to help:

a. absorb infra red light
b. make them easier to clean
c. eliminate back surface reflections
d. reduce the cost

Answer 4

b. make them easier to clean

Question 5

Transition lenses are darkest on:

a. warm & sunny
b. warm & cloudy
c. cold & sunny
d. cold & cloudy

Answer 5

c. cold & sunny

Question 6

Which of the following UV segments is transmitted to the crystalline lens?

a. UVA
b. UVB
c. UVC
d. UVS

Answer 6

a. UVA

Question 7

Which of the following lens options would be most beneficial when driving at night?

a. UV coating
b. polarized lenses
c. A/R coating
d. yellow tint

Answer 7

c. A/R coating

Question 8

All of the following will reduce lens thickness except:

a. aspheric curves
b. high index of refraction
c. smaller ED
d. higher specific gravity

Answer 8

d. higher specific gravity

Question 9

The best way for the patient to understand the benefits of polarized lenses:

a. articles about polarized lenses in the waiting area
b. display in the store window
c. explanation of the features & benefits
d. hands on demonstration

Answer 9

d. hands on demonstration

Question 10

Aspheric plus lenses have the following characteristics except:

a. reduced pincushion distortion
b. reduce thickness
c. improved off axis acuity
d. increased magnification

Answer 10

d. increased magnification

Question 11

We can get cataracts and wrinkles from the UVA spectrum of ___ to ___ nm.

Answer 11

330-400

Question 12

What does a high ABBE value of a lens material indicate?

a. low chromatic aberration
b. high chromatic aberration
c. cloudiness
d. it’s very heavy

Answer 12

a. low chromatic aberration

Question 13

Which two lens materials are the best choice for high impact resistance?

Answer 13

polycarbonate & Trivex

Question 14

Ultraviolet coating blocks light up to which wavelength?

Answer 14

400 nm (“UV 400”)

Question 15

What is the approximation formula for calculating a change in vertex distance?

Answer 15

dD2/1000

D2=”D squared”

Question 16

State the vertical imbalance formula.

Answer 16

Prism = Dd/10

Question 17

True or false.

The effective power is what we order from the lab.

Answer 17

False. The compensated power is what we order.

Question 18

Asymmetrical PALs push the majority of the astigmatism to the _____ side of the lens.

a. temporal
b. nasal
c. convex
d. concave

Answer 18

b. nasal

Question 19

True or false

A variable segment inset adjusts for the prismatic effect created by a middle corridor.

Answer 19

true