How Vision Works


Lt Col Reynolds
The cornea, lens, and retina are three important parts of the eye that interact to provide sight. Dr. Patel, can you tell us how these parts of the eye work together?

Dr. Patel
Absolutely, Dr. Reynolds. Light rays enter the eye through the cornea. When light strikes the cornea, it bends, or refracts, the incoming light. The light then passes through the lens, which further focuses that light onto the retina, a layer of light-sensing cells lining the back of the eye.

To see clearly, the cornea and lens must focus the light rays to meet precisely on the retina. The retina then converts the light rays into impulses that are sent through the optic nerve to the brain, which interprets the impulses as images.

The refractive process is similar to the way a camera takes a picture. Think of the cornea and lens as the camera lens, and the retina as the camera film. If the cornea and lens do not focus properly, the camera film, or retina, receives a blurry image.