We just learned about the Retina at the back of the eye.
Another part of the eye is the Lens.
This is a part of the eye right behind iris and pupil.
It is clear and works like a magnifying glass to help the eye focus on things close or far away.
The eye has muscles to push and pull on the lens to change the focus.
(from: wikipedia - lens (anatomy))
Kid Facts - Blast from the past: Dentin