Stereopsis and Depth perception

Question 1

What is retinal correspondence?

Answer 1

Enables binocular visual direction perception while maintaining single vision

Images on corresponding points are perceived as coming from equisidant targets

Question 2

What is the law of sensory correspondence?

Answer 2

States that existence of corresponding retinal elements with their common relative subjective visual direction is the essence of binocular vision

Question 3

What is retinal disparity (Binocular disparity)?

Answer 3

An angular subtense of the deviation of an image from corresponding points

Question 4

What is a horopter ?

Answer 4

The sum of all locus points in visual space that stimulate corresponding retinal points

Question 5

What is stereopsis?

Answer 5

Perception of a single, fused image of an object within the panum’s area

Question 6

What happens with a motor alignment problem (strabismus)?

Answer 6

Does not allow both eyes to look at a single object simultaneously
- Pathological diplopia can occur and there is a loss of fusion & stereopsis capacity

Question 7

What happens when binocular sensory development is compromised?

Answer 7

This does not allow two similar images for fusion

• causes aniksonia, significant blur or eye disease can cause this
• Eyes misalign (strabismus) in response to loss of sensory glue of fusion in the visual cortex

Question 8

What is fixation disparity?

Answer 8

It is a very slight visual axis misalignment

This misalignment falls within the panums fusional area so no diplopia is experienced

Question 9

What can fixation disparity be accompanied by?

Answer 9

• Significant dissociated heterophoria
• Reduced fusional reserves range
• symptoms of asthenopia