3D Television Technology

Stereopsis

How can you tell how far away an object is? When you look at a cup sitting on a table, you can usually estimate that it is a meter away. Your brain is using something called stereopsis.

When you look at something, you are actually taking two different pictures of the object; one with your left eye and one with your right. Since both of your eyes are not in the same place, your left eye and your right eye see a slightly different picture (this phenomenon is known as parallax). You can actually see this yourself. Look at something close to you in the room. Now look at it with your right eye closed. After you have done that, look at it with your left eye closed. If you look carefully, the picture you see with your left eye will be slightly different than the one you see with your right eye.

A set of eyes view a near object and a distant object.[1]

The diagram shows how your brain would see two different objects - one farther away than the other. If you look, you will see that the objects have a large distance between them when viewed by the left eye but look close together when viewed by the right eye. Your brain uses these slight differences in the images coming from your left eye and your right eye to determine how far away an image is. This is what stereopsis is all about.