How the Eye Works

The sclera (the "white") surrounds most of the eye and gives it its structural strength. In the front of the eye is the cornea, transparent tissue that sticks out slightly from the sclera. Just behind the cornea, and easily seen through it, is the iris, which is the part of the eye with the characteristic brown, blue, hazel, or green color. There is a circular hole, the pupil, in the center of the iris. It appears black, because the interior of the eye is designed to absorb light, not to reflect it.