Another fun eye/brain fact: There are two “outputs” for each eye. One goes to your occipital lobe, in the back, and really processes the image (“That’s a cup, it <holds liquid> <is firm with a medium weight>…” etc) and one goes to your brain stem, which processes movement.

It’s possible to have the connection to the occipital lob severed, but not to the brain stem. It’s a condition called blindsight. The result is that if you showed someone a cup, they wouldn’t be “see” it; they wouldn’t know what it is and wouldn’t register you were showing them anything at all… but if you tossed it to them they could catch it.