Binocular and Spatial Vision (M2)

Question 1

How does depth perception of monocular vision differ from binocular vision?

Answer 1

monocular much worse than binocular

Question 2

What is the vision of two-eyed vertebrates in which the eyes work together? 1. What is different about theses animals anatomically compared to when function separately? 2

Answer 2

1. ambiocular

2. partial decussation of the optic nerves

Question 3

What is a major difference between congenital nystagmus and acquired nystagmus?

Answer 3

oscillopsia is common in acquired

Question 4

What is the direction of the line of fixation measured from the straight ahead position (with symbol)?

Answer 4

ocular direction (α)

Question 5

What is the theory that ocular, oculocentric, or egocentric direction is that of the dominant eye? 1. Is this true in most cases? 2

Answer 5

1. dominant eye theory

2. no

Question 6

What does anomalous retinal correspondence (ARC) prevent?

Answer 6

confusion and diplopia

Question 7

What is the line of sight perpendicular to an extended source (wall, etc) called?

Answer 7

subjective straight ahead (SSA)

Question 8

What is the ocular disorder in which there are problems with communication between afferent and efferent systems that presents in the first 6 months of life?

Answer 8

infantile nystagmus syndrome or congenital nystagmus

Question 9

What is the angle between the line of fixation and optic axis? 1. What does this angle indicate? 2

Answer 9

1. gamma (γ)

2. the nasal-temporal division in ambiocular vision

Question 10

What is the concept of seeing double at any distance other than the distance you are fixating called?

Answer 10

physiological diplopia

Question 11

How does brightness perception of monocular vision differ from binocular vision?

Answer 11

Normally the same (luminance of two eyes is the average, no the sum of the luminances of the two eyes)

Question 12

Which direction is the slow phase for a vestibular nystagmus?

Answer 12

drift towards damaged (hypo) side because sensing body rotation to opposite side

Question 13

What is harmonious anomalous retinal correspondence (ARC) easily confused with?

Answer 13

lack of correspondence

Question 14

How does light detection of monocular vision differ from binocular vision?

Answer 14

improved detection with two eyes

Question 15

How does light adaptation of monocular vision differ from binocular vision?

Answer 15

eyes dark adapt independently of each other

Question 16

What is the result from stimulation of non-corresponding retinal points? 1. What is it equal to? 2

Answer 16

1. retinal or absolute disparity

2. angular separation of images

Question 17

What is the visual direction of an object specified relative to the “line of fixation” (with symbol)?

Answer 17

oculocentric direction (β)

Question 18

What type of eye placement do prey animals generally have? 1. Predator animals? 2

Answer 18

1. laterally placed eyes

2. frontal eyes

Question 19

For vestibular nystagmus, what direction does the object appear to be moving during the slow phase eye movement? 1. Why? 2

Answer 19

1. opposite the eye movement

2. no body rotation actually occurred

Question 20

Is the far/near AC/A or the gradient AC/A always larger? 1. Why? 2

Answer 20

1. far/near

2. proximal vergence is not actually constant

Question 21

What occurs during the adaptation to glasses for a patient?

Answer 21

adapt limb proprioception to match vision

Question 22

What is the probability light detection equation?

Answer 22

q = 1 - (1 - p)^n
q = prob in two eyes
p = prob in one eye
n = number of eyes

Question 23

What is it called when one eye is the favored side of the bilateral pair?

Answer 23

ocular dominance

Question 24

Where is the egocenter located in binocular vision?

Answer 24

between the eyes about 10cm behind the plane of the eyes

Question 25

For acquired nystagmus, what direction does the object appear to be moving during the slow phase eye movement? 1. Why? 2. During fast phase? 3

Answer 25

1. opposite the eye movement
2. alpha is not being sensed
3. suppression and omission during fast phase

Question 26

How does transient light adaptation of monocular vision differ from binocular vision?

Answer 26

interactions btw the eyes increase the threshold in one eye near the onset and offset of the background in the other eye

Question 27

What are the ocular signs found in infantile nystagmus syndrome or congenital nystagmus?

Answer 27

1. uniplanar
2. reduced with convergence
3. pendular in straight ahead and jerk at sides
4. should have null position
5. has unique acceleratory slow phase
6. NEVER have oscillopsia

Question 28

What is the body reference point for egocentric direction called?

Answer 28

the egocenter

Question 29

What is the sign convention for the specification of direction?

Answer 29

1. right and up are positive directions (+)

2. left and down are negative direction (-)

Question 30

What are retinal points (one in each eye) that have the same oculocentric direction called?

Answer 30

corresponding points (β(L) = β(R))

Question 31

What is the coordinated behavior of the two eyes in the perception of space called?

Answer 31

binocular vision

Question 32

What are the major benefits of ambiocular vision?

Answer 32

1. stereopsis

2. better visual acuity (smaller angle γ so better optics)

Question 33

Because the prismatic effects of plus lenses require the eye to rotate more than the normal amount by moving the image, what is the patient really doing?

Answer 33

patient is pastpointing

Question 34

What is the theory that ocular, oculocentric, or egocentric direction is the average of the two eyes? 1. Is this true in most cases? 2

Answer 34

1. Cyclopean theory

2. yes

Question 35

What happens to the perception of the subjective straight ahead with left neglect?

Answer 35

right side of wall appears closer and left part appears further away

Question 36

What is the visual direction of an object specified with respect to the straight ahead (with symbol)?

Answer 36

egocentric direction (χ)

Question 37

What is the specific sensation of depth characteristic of ambiocular vision?

Answer 37

stereopsis

Question 38

What is the vision of two-eyed vertebrates in which the eyes function separately called? 1. What is different about theses animals anatomically compared to when work together? 2

Answer 38

1. utrocular

2. complete crossing of the optic nerves

Question 39

What is the angle between the optic axis (with eye centered in orbit) and the body midline (with symbol)?

Answer 39

ocular laterality (ω)