Human vision and function/Part 2: Understanding vision: visual acuity, colour vision and 3D perception/2.3 Depth perception

2.3 Depth perception
At the end of this topic you will gain an introductory understanding of how binocular vision and stereopsis (3D vision) work and be able to describe the physiological basis for design of stereoscopic (3 D) vision tests.

Task 1
The sensation of depth occurs when the two eyes look at two slightly different objects, each object falling on either retina, and blend them into one. The perception of depth or 3D is termed "stereopsis" and is a binocular phenomenon, meaning that both eye must be working perfectly together.

Start by watching the YouTube playlist to understand stereopsis.

Task 2
Watch this very short video and complete the activity it asks you to do which demonstrates the principle of binocular vision and stereopsis.

Supplementary reading
1. Wikipedia has a great overview of Stereopsis.

2. For more detailed reading, see the chapters on Space Perception and Depth Perception by Kalloniatis M & Luu C (2014).

Revision Questions
Discuss the answers to these questions on your group LMS forum.

1. Why must both eyes work together in order to perceive stereopsis?

2. What was the purpose of the visual cliff experiments?

3. There are two ways to determine depth. What are these?

4. What type of patterns does the Randot stereotest use to assess stereopsis?

5. What type of depth cue us interposition? Describe how it works.

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