The Process of Sight

The process of sight is indeed awe-inspiring. The eye acts like the camera that takes a picture. Every camera must have a lens to properly focus the picture. Your eye has a lens, too, which lies directly behind the pupil in the sac-like capsule. Your lens, which is about the size of an "M&M," is normally clear and transparent. It focuses images onto the retina, which acts as the film that records the picture. The picture is then transmitted by the optic nerve to the brain, where the image is interpreted. Its the brain that does the actual seeing.

The lens never stops growing, so an adult's lens is larger, thicker and more opaque than a child's.

By the time a person is 40, the lens is less flexible and can cause near-vision problems which lead people to say things like "My arms are not long enough," or "I can't read small print." This problem is caused by an overgrown lens, which occurs long before the cloudiness, or cataract, begins.

At age 65, this overgrown lens blocks one-third of the light entering the eye.