system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: How come our eyes can scroll when focusing on a moving object, but we can't casually scroll our eyes when not focusing on something?
gpt
The control systems for your eyes are *specifically adapted* to help you fix your vision on specific objects so you can see them. There is no advantage to being able to move your eyes arbitrarily, so the control system has no special features to make this easy.