system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: why can you move one eye inward independently but not outward?
gpt
"Moving one eye inward" uses the same movements as focusing on a point very close in front of one eye. You don't actually need to move your eyes "independently" to do this; so long as the focal point is in front of one of them, that eye will appear not to move, but it can still be tracking a point together with the other eye.

Moving one or both of your eyes *outward* can't be done by focusing on a point.