Why cant you look with you left eye to the left and right eye to your right?

Question

Just wondered why you can cross your eyes... giving them independent movement but not the other polar directions.... even one up and other down....

Answer 1

Actually you can; those "Magic Eye" 3D diagrams require you to move the left eye to the left and the right eye to the right to work. If you concentrate, you can also "uncross" your eyes while looking at near or far.

It is easier to cross your eyes because the mechanism that allows you to focus at near also causing eye crossing. When most people deliberately cross their eyes they will also blur them so that the focusing act helps with causing crossing.

Vertical crossing movement is more difficult, the eye muscles are not designed to allow much of this. But if you use prisms or "3D" pictures that demand vertical misalignment it can be done.

Answer 2

It's part of being able to see in 3-dimensions. Your eyes actually cross a little whenever you are looking at something very close to your face. In order to see in the distance, your eyes only need to look straight ahead. The farther the object you focus on, the farther apart your eyes will move, but not so far to require the "opposite" of crossed eyes.

Your eyes can't move independently of each other, because that would mean being able to focus on two completely different images at the same time. Our brains are only designed to handle 3D information, not 4D or more, so it's not physiologically necessary for our eyes to move that way.

Answer 3

the answer is neuromuscular and i can't explain it in just words.

i couldn't find anything that shows it from my search. Go to a library and look at the anatomy of the eye, then its innervation. You will see that the nerves that do one thing depend mostly on visual cues and are the same for both eyes. you can only make your eyes focus on one thing so its impossible to look at 2 different things. moving them both inwards can still be a focusing on one thing. moving them outward or up and down would have to be 2 things. A lazy eye will drift from focus, but usually the reception of the eye is not transmitted from the lazy eye to the brain - so the lazy part is the muscle and the nerves as well. That is when it gets really interesting in neurology.

Answer 4

you have a center for convergence [ cross your eyes ] that you use in doing near tasks , you can use it voluntarily but you don't have any other centers to make other movements you mentioned