3. Stereopsis and Fusion

Question 1

Which cues are needed for depth perception?

Answer 1

1. Ocular signals - vergence and accomodation
2. Monocular cues
3. Stereopsis - Disparity

Question 2

As disparity increases what happens?

Answer 2

The greater the disparity = greater sense of depth. This is as long as it is within panum’s fusional area, if not then diplopia.

Question 3

What is absolute depth?

Answer 3

Distance of object from observer

Question 4

What is relative depth?

Answer 4

Comparison of distance between two objects

Question 5

What are the two types of depth and which one does stereopsis process and how?

Answer 5

1. Absolute depth
2. Relative depth

Stereopsis processes only relative depth.
It can code the difference in disparities between objects.

Question 6

Outline 3 charactersitcs for stereoacuity

Answer 6

1. At near stereoacuity is strongest.
2. Larger disparity for those with larger IPD’s
3. Good stereopsis is 30-60 secsArc

Question 7

What is considered as good stereopsis?

Answer 7

30-60 sec/arc

Question 8

Draw a diagram showing panum’s fusional area

Question 9

Draw a graph showing panum’s fusional area