How do your eyes work?

There are many different parts of the eye that help to create vision. We “see” with our brains; our eyes collect visual information and begin this complex process.

• Light passes through the cornea, the clear, dome-shaped surface that covers the front of the eye. The cornea bends – or refracts – this incoming light.
• The iris, the colored part of the eye, regulates the size of the pupil, the opening that controls the amount of light that enters the eye.
• Behind the pupil is the lens, a clear part of the eye that further focuses light, or an image, onto the retina.
• The retina is a thin, delicate, photosensitive tissue that contains the special “photoreceptor” cells that convert light into electrical signals.
• These electrical signals are processed further, and then travel from the retina of the eye to the brain through the optic nerve, a bundle of about one million nerve fibers.

Courtesy: National Eye Institute, National Institutes of Health (NEI/NIH)