Test 1 Review

Question 1

In the afterimage test, where would a patient with a left esotropia view the vertical line?

Answer 1

Right side

Question 2

In the afterimage test, where would a patient with a right esotropia view the vertical line?

Answer 2

Left side

Question 3

In the afterimage test, where would a patient with a left exotropia view the vertical line?

Answer 3

Left side

Question 4

In the afterimage test, where would a patient with a right exotropia view the vertical line?

Answer 4

Right side

Question 5

In what scenario would type I paradoxical ARC be found?

Answer 5

Undercorrection of esotropia

Question 6

In what scenario would type II paradoxical ARC be found?

Answer 6

Overcorrection of exotropia

Question 7

What is the definition of unharmonious ARC?

Answer 7

When there is a subjective angle of strabismus, but it is smaller than the objective angle (H)

Question 8

In UNHARC, where will the angle “a” be located?

Answer 8

Between the fovea (f) and the straight-ahead point (z)

Question 9

What angles coincide in harmonious ARC?

Answer 9

“a” and “z”

Question 10

What horoptor anomaly may an early onset esotropia patient have?

Answer 10

Flom notch

Question 11

What happens to the horopter in an intermittent esotrope?

Answer 11

The horopter gets flatter - IVD horopter

Question 12

In ARC, the size of angle “a” is typically related to what?

Answer 12

The size of the strabismus

Question 13

Which is not stable, and may be altered by image luminance and contrast, ARC or NRC?

Answer 13

ARC

Question 14

If a patient develops strabismus after age 7, will they develop ARC?

Answer 14

Probably not

Question 15

In the Pulfrich phenomenon, why is there a sense of rotation when viewing a pendulum swinging?

Answer 15

One eye is “dimmed”, and there is a lag of the neural signals reaching the brain

Question 16

A patient demonstrates the Pulfrich phenomenon and reports that the object appears to be moving in a clockwise direction. Which eye is affected?

Answer 16

Left eye

Question 17

A patient demonstrates the Pulfrich phenomenon and reports that the object appears to be moving in a counter-clockwise direction. Which eye is affected?

Answer 17

Right eye

Question 18

Global stereo is related to (coarse/fine) stereo.

Answer 18

Fine

Question 19

Local stereo is related to (coarse/fine) stereo.

Answer 19

Coarse

Question 20

Which variety of stereo is more sensitive to binocular anomalies?

Answer 20

Global

Question 21

Coarse stereo uses which pathway?

Answer 21

Magnocellular pathway

Question 22

Fine stereo uses which pathway?

Answer 22

Parvoceullular pathway

Question 23

Which type of stereo (global/local) is based on images that can be recognized monocularly as well as binocularly?

Answer 23

Local stereo

Question 24

What does local stereo generate info for?

Answer 24

Lines, edges, contour…simple things

Question 25

In patent stereo, depth is proportional to what?

Answer 25

The disparity

Question 26

Which is more high quality stereo, patent or latent?

Answer 26

Patent

Question 27

Where is patent stereo found (think about looking at a horopter/Panum's area picture)?

Answer 27

Within, and just outside of Panum's area

Question 28

What is perceived with latent stereo?

Answer 28

Near or far, but not actual depth

Question 29

What part of the eye has the best stereo acuity?

Answer 29

Fovea

Question 30

What factors reduce stereo acuity?

Answer 30

Low contrast Unequal retinal contrast The color blue Short exposure time

Question 31

What is the equation to get disparity in seconds of arc?

Answer 31

n = PD * delta d / D^2 Conversion factor of 206,000 and change PD = 2a

Question 32

If the PD is larger, what happens to the disparity?

Answer 32

It increases

Question 33

If the object gets closer, what happens to the disparity?

Answer 33

It gets larger

Question 34

Disparity is ___ proportional to the square of the viewing distance.

Answer 34

Inversely

Question 35

What are the binocular depth cues?

Answer 35

Convergence | Stereopsis

Question 36

What is convergence micropsia?

Answer 36

Increased convergence innervation tells the brain that the object is getting closer, while the retinal image size remains unchanged. The observer perceives that the object is getting smaller

Question 37

What does SILO stand for, and what is its relationship with convergence micropsia?

Answer 37

Small in, Large out | That is the sensation when convergence micropsia occurs

Question 38

What is stereopsis primarily based on?

Answer 38

Horizontal relative binocular disparity

Question 39

What does absolute depth perception tell you?

Answer 39

How far objects are from themselves or other objects

Question 40

What does relative depth perception tell you?

Answer 40

About the comparison of depth (% or ratio)

Question 41

How might disparity be calculated?

Answer 41

``` n = PD * delta d / D^2 n = alpha - beta n = gamma L - gamma R ```

Question 42

What are the monocular non-pictorial cues?

Answer 42

Accommodation Motion parallax Kinetic depth effect

Question 43

Which of the monocular non-pictorial cues is related to motion parallax?

Answer 43

Kinetic depth effect

Question 44

Which is the weakest non-pictorial cue?

Answer 44

Accommodation

Question 45

In motion parallax, objects nearer than the fixation point have which motion?

Answer 45

Against

Question 46

In motion parallax, objects farther than fixation have which motion?

Answer 46

With

Question 47

When looking at a forced vergence fixation disparity curve, what is the y-axis?

Answer 47

Fixation disparity

Question 48

When looking at a forced vergence fixation disparity curve, what is the x-axis?

Answer 48

Associated phoria

Question 49

What is an associated phoria?

Answer 49

The amount of prism necessary to eliminate fixation disparity

Question 50

What is heterophoria?

Answer 50

Overall deviation as tested by cover test