(G3) The Binocular Vision Examination

Question 1

Binocular Vision anomalies in terms of two broad categories:

Answer 1

(1) BV is maintained, often at the cost of an amount of stress— including phorias, fusional vergence anomalies, fixation disparity, & anomalies of accommodation)
(2) BV is absent— including strabismus (tropia or squint) & amblyopia.

Question 2

convergence that is associated with accommodation

Answer 2

Accommodative convergence

Question 2

determines, to a great extent the distance phoria

Answer 2

Tonic convergence

Question 3

an excess of tonic convergence result in

Answer 3

Esophoria

Question 3

deficiency of tonic convergence result in

Answer 3

Exophoria

Question 4

Deficiency of accommodative convergence result in

Answer 4

Exophoria at near

Question 4

For someone who is orthophoric at distance, excessive amount of accommodative convergence result in

Answer 4

Esophoria at near

Question 5

convergence that compensates for any excess or deficit in tonic or accommodative convergence

Answer 5

Fusional convergence

Question 6

can compensate for a deficiency of tonic or accommodative convergence

Answer 6

Positive fusional convergence

Question 6

it prevents a person from seeing double, or prevents a phoria from being a tropia

Answer 6

Fusional convergence

Question 7

To test proximal convergence, hold an object such as pencil at normal reading distance & slowly move it toward your nose until you see two pencils, this exercise is known as

Answer 7

Pencil pushup

Question 7

can compensate for an excess of tonic or accommodative convergence

Answer 7

Negative fusional convergence

Question 7

occurs because of awareness of nearness

Answer 7

Proximal convergence

Question 8

method of eliminating stimuli to fusion routinely used for clinical phoria measurement involve use of

Answer 8

Dissociating prism

Question 8

simplest method to eliminate stimuli to fusion

Answer 8

Occlude one eye, done in cover test

Question 9

position of the eyes taken by two visual axes with respect to each other when all stimuli to fusion have been eliminated

Answer 9

The Phoria Position

Question 10

used to measure a lateral phoria

Answer 10

Vertical dissociating prism

Question 10

used to measure vertical phoria

Answer 10

Horizontal dissociating phoria

Question 11

if visual axes are found to be parallel when px views a distant object & all stimuli to fusion have been eliminated

Answer 11

Orthophoria

Question 12

if visual axes converge toward one another when eyes are dissociated the individual has

Answer 12

Esophoria

Question 13

if visual axes diverge toward one another when eyes are dissociated the individual has

Answer 13

Exophoria

Question 13

if one visual axis deviates above or below the other

Answer 13

Hyperphoria

Question 14

stimulus to accommodation is approximately 6m & 40cm

Answer 14

0.17D (6m)
2.50D (40cm)

Question 14

in routine optometric practice, phorias are measured at distances of

Answer 14

6m (far) and 40cm (near)

Question 14

at ______, stimuli to both accommodation & convergence are considered to be zero

Answer 14

6m

Question 15

stimulus to convergence is approximately

Answer 15

1△

Question 16

at 40cm, the stimulus to accommodation is

Answer 16

2.50D

Question 16

the stimulus to convergence for an individual with 64mm PD is

Answer 16

15△

Question 16

most people are orthophoric at distance, thought to be due to

Answer 16

Fusion adaptation process

Question 17

_______ described that most people are ortho at distance due to “fusion adaptation process”

Answer 17

Carter (1963,1965)

Question 18

if an individual is found to have significant distance phoria, it is because he/she does not possess-or has a deficient “fusion adaptation process”

Answer 18

Fusion adaptation process theory