We just learned about the Unconsciousness.
Another part of sleep is called Rapid Eye Movement.
Sometimes when you are sleeping and your eyelids are closed, your eyeballs will move around like they are wiggling.
During this time the brain is active and the eyes are moving, but you are sound asleep.
Because the eyes are moving quickly, they call it REM for Rapid Eye Movement.
During other times of sleep the eyes don't move as much.
(from: wikipedia - rapid eye movement sleep)
Kid Facts - Blast from the past: Cochlea
