When we look around, we understand that objects far from us at the same distance are different in size, or one of them is behind another. Why are we seeing in three dimensions, the present position in relation to other things instead of just seeing a plane?

The point is that when we “see” things that we see them not only with our eyes, but also with the mind. We see things in light of experience. Our brain, based on some experience, helps us interpret what we see. And if the brain could not use the experience that enables it to interpret what we see, we could come in complete confusion.

For example, the experience gives us an idea about the size of objects. A man standing in a boat offshore, it seems much less of a man standing on the shore. But you cannot say that one person is very large, and the other is very small. You say that one man is standing closes, and the other is far away from you.

What else of the knowledge is using your brain? One of them – a prospect. You know that when you look into the distance on the track, they come together. Taking into account the width of the path, we judge the distance. Experience tells you what we see close objects clearly and sharply, and the remote seem dim.

With experience, you can also learn to “read” the shadows. They give you an idea of ​​form and interaction of objects. Similar objects often cover parts of the objects that are farther. So you can say to you closer – or tree house.

Head movement helps you determine what’s next from you – a tree or pole. Close one eye and turn heads. The distant object moves relative to you, and near the object will move differently. Even focusing my eyes, we can form an opinion on the distance to objects. You feel tense when you first view focuses on close objects, and then to distant ones.

In the end, experience is generated in the combined activity of both eyes. If the objects are moving towards you and you are trying to focus on them, look, your eyes converge at one point and eye muscles are tensed. Voltage gives an idea of ​​the distance. Another indication of the distance lies in the fact that each eye sees a different picture. The difference in the image helps you get a correct idea of ​​the distance. All this explains why the ability to see in three dimensions is based on past experience, mapped in the brain.