The eye is like a camera . The front part consists of the cornea, the transparent area in the center, which is surrounded by the sclera, as the white of the eye is called. Behind the cornea is the colored part, in the middle of which is the pupil, which grows larger or smaller to control the amount of light let into the "camera." The clear, transparent lens, located slightly in back of the front surface, focuses the image on the retina, which is about three quarters of an inch behind it. The optic nerve carries the picture from the retina to the brain. The eye also contains muscles to do this work and fluid to keep the parts in working condition.