system
Given the following post, respond as if you're commenting on Reddit:
human
eli5: Why most people can turn both eyes inwards but not in the opposite direction?
gpt
Turning eyes inward is a very natural motion, for focusing both eyes on something that is very close to your face. You naturally do it all the time.

Pointing your eyes outward is not a "natural" motion, because there is no occasion where you would focus your eyes on two different objects. Your brain is inherently trained to use binocular (two eyes on one object) vision, not monocular (one eye on one object).