Eye

20.3 Eye The eye is a complex and delicate organ. It is protected by the surrounding bones, eyelids, eyelashes, eyebrows, and tears. Light enters the eye through the cornea (the outer surface) and then an opening (called the pupil), then passes through a lens which helps clarify or focus what is being seen. The light then hits the back of the eye called the retina which sends the message (of what is being seen) through the optic nerve to the brain for interpretation. It is the job of the pupil to allow the correct amount of light into the eye. When there is plenty of light, the pupil constricts to allow only a small amount of light to come in. When there is little light, the pupil opens wide to allow in the maximum amount of light.