Physiology of Binocular Vision

Question 1

Normal Binocular Vision

Answer 1

bifoveal with no deviation

Question 2

Abnormal Binocular Vision

Answer 2

fovea of one eye projects with a non-fovea point of other eye

Question 3

Retinal Element

Answer 3

where stimulus reacts on the retina in relation to the fovea

Question 4

Matching Retinal Elements

Answer 4

have same visual field

represent corresponding retinal points

Question 5

Visual Direction

Answer 5

all points falling along a visual line (horopter)
identifies where a light is coming from
subjective

Question 6

Eccentric Fixation

Answer 6

in strabismus

non-fovea point assumes characteristics of the principal visual direction

Question 7

Visual Axis

Answer 7

line that connects an object with its retinal image

Question 8

Monocular Fixation

Answer 8

only one line of direction goes to fixation

Question 9

Local Sign

Answer 9

ability to identify fixed direction in space

objects in same direction will be in a single visual direction in binocular vision

Question 10

Corresponding Retinal Points

Answer 10

retinal elements in each eye that lie in same visual direction/ field

Question 11

Fovea has a _____ receptive field

Answer 11

small

allows for more precise visual direction

Question 12

Peripheral Retina has a _____ receptive field

Answer 12

large

Question 13

Metamorphosia

Answer 13

disrupts visual direction at fovea

Question 14

Horopter

Answer 14

line of vision

objects on horopter project to corresponding retinal points and appear as a single image

Question 15

Points not on Horopter

Answer 15

seen by different retinal areas

double vision- two different visual directions

Question 16

Panum’s Fusional Area

Answer 16

narrow band around horopter that allows objects from different retinal points to be seen as single
narrow around fixation, broad in periphery

Question 17

Broader Panum’s Fusional Area in periphery is because…

Answer 17

maintain vision because of eccentricity, which otherwise causes a decrease in vision
eliminates diplopia

Question 18

Panum’s Fusional Area and Stimulus

Answer 18

sharp image- smaller area

fuzzy image- larger area

Question 19

Uncrossed Diplopia

Answer 19

focusing beyond the horopter,

nasal retinal elements do not have same visual directions

Question 20

Crossed Diplopia

Answer 20

focusing in front of horopter

temporal retinal elements do not have the same visual directions

Question 21

Obtaining the same visual direction

Answer 21

temporal retinal in one eye with a nasal element in the other
image will fall on horopter

Question 22

Fusion

Answer 22

unification of both eyes to form an image
image needs to be the same size and shape
dissimilarity is tolerated better at periphery than at fovea because of larger receptive field

Question 23

Sensory Fusion

Answer 23

integration of images on corresponding retinal points to form an image

Question 24

Motor Fusion

Answer 24

vergence movement to maintain retinal images at corresponding retinal points