We just learned about Rapid Eye Movement.
Another part of how eyes work is Depth Perception.
Because humans have two eyes that are set apart from each other, they can look at the world and tell if something is close and if something is far away.
With just one eye it is very hard to tell that, but because two eyes are looking at something from different angles, the human brain can use those two different pictures and figure out if something is close or far.
(from: wikipedia - depth perception)
(from: wikipedia - binocular vision)
Kid Facts - Blast from the past: Foliate Papillae
