Press the l key to open the language menu.
Skip Main Navigation and go to Content

The retinal implant provides stimulation to induce visual perception in blind individuals.

About The Eye

Anatomy

Anatomy of the Eye

Credit: National Eye Institute, National Institutes of Health

How We See

Light enters the eye via the cornea; the amount of light that enters is controlled by the iris, which expands or contracts the pupil in response to the brightness of the scene. The lens then focuses the light into a patterned image on the retina. Cells in the retina called "rods" and "cones" (photoreceptors) convert the light into electrical impulses, which are sent to the brain via the optic nerve. The brain then interprets the impulses and creates what we "see".

 

Eye Disease: Retinitis Pigmentosa (RP)

Retinitis pigmentosa (RP) is a disease that leads to degeneration of the rods and cones of the retina; it is one of the leading causes of inherited blindness.

Symptoms may appear at adolescence, but severe vision problems do not normally occur before early adulthood. In the early stages of the disease, people with RP experience loss of night vision and more difficulty seeing in low-light conditions. As the disease progresses, RP sufferers begin to lose peripheral vision and develop ‘tunnel vision’. In the most advanced stages, a person with RP may become completely blind.

Other forms of RP and related diseases include Usher syndrome, Leber’s congenital amaurosis, rod-cone disease, and Bardet-Biedl syndrome, among others.

Progression of RP