Depth perception allows us to judge how far away various objects are from us.
In order to achieve the highest levels of depth perception our two eyes must function together well. This allows us to see our world in 3 dimensions.
There are however monocular (one eye) cues to depth perception as well.
Two of the more common monocular cues to depth perception include:
1. Relative size of objects…. a tree that is closer to us appears larger than a tree that is farther away.
2. If one object partially blocks the view of another object we know it is closer.
The most important binocular cue to depth perception is a result of our two eyes receiving slightly different images. This is especially true when objects are close to us since the two eyes view the same object from significantly different angles. For objects that are further away the viewing angles become more and more alike which makes judging depth for objects further from us more difficult. For example if you were to view trees on the horizon it would be difficult, based on binocular cues, to determine which trees would be closer to you.
Another binocular cue occurs when we move slightly in space. Objects closer to us appear to move rapidly while objects further away appear to move more slowly. This phenomena is called motion parallax.
Tags: binocular vision, depth-perception, judging distances, monocular vision, parallax, relative size
