Overview
In many ways, your eye works like a camera. It lets light in through the pupil, which is like a camera’s aperture, or opening. The iris, which opens and closes like a camera’s shutter, controls the amount of light that gets into your eye. The light then focuses on the retina, which acts like the film in a camera to record the images that the light brings into your eye. The retina then sends the information to the brain to be developed, or interpreted.
Other parts of your eye support its main activity of letting you see. Some parts of your eye carry fluids, like tears and blood, to lubricate or nourish the eye. Others are muscles that control the eye’s movement. Some protect the eye from injury, like the lids and the epithelium (a kind of membrane) of the cornea. Finally, some parts act as messengers to send information to the brain. These parts include the nerves in the cornea that sense pain and the optic nerve behind the retina, which sends information on what you see to and from your brain.