Binocular and stereo vision

We all have two eyes? Are they really necessary? Can we not do with just one?
Here are some reasons to show that two eyes are better than one.

Each eye looks at an object and draws information about it. Because the eyes are not in the same position, each eye has a slightly different view, the net effect being that while both the eyes see almost the same, each eye sees a little bit extra. The brain matches the similarities in both the views, adds the extras from both eyes to get the impression of the object. Thus vision from both eyes or binocular vision is when both eyes work together to draw information about an object. The effect of this is very important. Binocular vision results in stereovision, which enables one to see and perceive three-dimensional objects. This provides depth perception and an ability to visually judge relative distances between objects.

To understand how the brain interprets the information obtained from the two eyes, try to focus each eye on a different object. For example, roll up a tube of paper and look through it with one eye. Place your open hand against the middle of the tube and look at it with the other eye. You will see your hand with a hole in it, for, the brain is receiving two very different images and putting them together.

A good binocular vision has the following abilities:
1. The ability to move the eyes across a sheet of paper , for example, when reading.
2. The ability to use both eyes together at the same time.
3. The ability of binocular depth perception.
4. The ability to judge distances.

These abilities are very important. Simple tests can be conducted to test binocular vision and an early examination can help rectify vision impairments.