Quiz 2

Question 1

Your pt wears +2.00DS SCL. The VA is decreased. In over-the-lens keratometry, the mires are irregular. What is the most likely reason?
Incorrect lens power
Keratoconus
Lenses are inside out
Uncorrected irregular astigmatism

Answer 1

Lenses are inside out

Question 2

Your pt wears -2.00DS GP CL's. In the over-the-lens keratometry, you find -0.75 x 180. Why is that?
Front toric lens
Lenses are inside out
Uncorrected irregular astigmatism
Lens flexure

Answer 2

Lens flexure

Question 3

In calculations, the refractive index of the cornea is considered 1.3375. Why is that?

a. Because it is close to the index of tears
b. Because this is the refractive index of the human cornea
c. Because this is the average of the tears and the corneas refractive indices
d. Because the cornea is considered a single surface

Answer 3

d. Because the cornea is considered a single surface

Question 4

Your pts. wears -10.00D spectacle lenses 12mm from the cornea and wants to use contact lenses. What is the appropriate CL’s?

Answer 4

-9.00D

Question 5

A daily wear CL should have atleast which of the following Dk/t values?
14
24
42
87

Answer 5

24

Note: 87 is for extended wear

Question 6

Which of the following is a true description of Plasma treatment of lenses?
A coating that lasts about 1 week
A coating that lasts a few months
An intense surface cleaning
Uses a hot (500 C) plasma to break organic bonds

Answer 6

An intense surface cleaning

Question 7

Which of the following us an in-vivo test of CL wettability?
Sessile drop
Captive bubble
Break up time
Dk measurement

Answer 7

Break up time