exam2

Question 1

What is Fixational disparity?

Answer 1

a mismatch between stimulus to fusion and fusional response.

Question 2

What would happen is the mechanism perfectly aligned the visual axes on the fixation point?

Answer 2

1) The vergence demand would become zero and the stimulus to maintain the correct vergence would be lost.
2) Without the disparity vergence the eyes would go back to their resting position, which would lead the disparity to increase again and cause the eyes to swing back.
3) This is inefficient

Question 3

What is binocular disparity?

Answer 3

retinal disparity. this requires to motor activity

Question 4

How is fixation disparity determined?

Answer 4

By the resolution limits of the retinal regions. (Panums area)

Question 5

What is the range of FD?

Answer 5

centrally is 10-30 min arc = 0.75 prism

Question 6

What is gain?

Answer 6

how responsive the fine disparity vergence system is to retinal disparity.
testing is done at fixed distances

Question 7

What is the FD equation?

Answer 7

FD= DVD[1-(G/(1+G))] 
DVD= disparity vergence demand
G = gain