midterm exam

Question 1

What is the term for the part of the retina where we get our sharpest vision?

Answer 1

The macula.

Question 2

Which of these accurately describes astigmatism?

Answer 2

Light focuses at several different points.

Question 3

What occurs in esotropia?

Answer 3

One or both eyes turn inward.

Question 4

Which of these conditions causes severe impairment of peripheral vision?

Answer 4

Glaucoma.

Question 5

When you’re fitting people for glasses, you’ll measure their pupillary distance. What is this?

Answer 5

The distance from the center of one pupil to the center of the other pupil.

Question 6

Which of these frame styles will flatter the features of a person with a base-down triangular face shape?

Answer 6

Frames that are wider at the top than at the bottom.

Question 7

Which of these is the typical range for a pantoscopic tilt?

Answer 7

5 to 15 degrees.

Question 8

What is the focal length of a -3.00 lens?

Answer 8

-.333 meters.

Question 9

Which of these eyes has mixed astigmatism?

Answer 9

+1.25 -2.25 x 80.

Question 10

Which of these bifocal segments is a good choice for a pilot who needs to have good close vision through both the top and bottom of a lens?

Answer 10

A double D segment.

Question 11

What clear, glistening tissue covers the sclera?

Answer 11

The conjunctiva.

Question 12

Which of these problems occurs in macular degeneration?

Answer 12

Poor central vision.

Question 13

Which of these very common frame materials is hypoallergenic?

Answer 13

Titanium.

Question 14

What will you use a distometer for?

Answer 14

Measuring vertex.

Question 15

What do you do when you transpose a prescription?

Answer 15

You change it from a negative cylinder form to a positive cylinder form.

Question 16

Using a lens clock, you find that the front surface of a lens reads -2.25. The back surface reads -1.50. What is the power of the lens?

Answer 16

-3.75.

Question 17

What is the range of the visible light spectrum?

Answer 17

380 to 760 nm.

Question 18

David wears bifocals. His right-eye prescription is -2.00 -1.25 X 90 with an add of +2.50. What is the total power of this lens in the add portion?

Answer 18

+0.50

Question 19

Take a look at the following prescription:

OD: +2.50 +0.75 x 093

OS: -3.50 +1.25 x 180

What numbers do you get when you transpose this prescription?

Answer 19

OD: +3.25 -0.75 x 003 and OS: -2.25 -1.25 x 090

Question 20

Which of these is an accurate statement about pantoscopic tilt?

Answer 20

Each additional two degrees of pantoscopic tilt will move the optical center of a lens down one millimeter.

Question 21

The total power of a lens is +1.50. The back surface measurement is -6.5. What is the front surface measurement?

Answer 21

+8.00.

Question 22

Which of the following materials is excellent for children’s sports frames because it doesn’t shatter easily?

Answer 22

Polycarbonate.

Question 23

How does light behave when it moves from one medium to another?

Answer 23

Light bends toward the normal when it moves from a rarer to a denser medium.
Correct

Question 24

Which list below contains three refractive errors?

Answer 24

Astigmatism, myopia, and hyperopia.

Question 25

Which of these is an accurate statement about progressive lenses?

Answer 25

Adaptation to progressive lenses is difficult if the monocular PDs are not measured correctly.