The RETINA is the inner layer of the eyeball. It is composed of nerve tissue which senses the light that enters the eye. These nerves send messages back to the brain which translates the messages into the images that we see. The retina is a complex structure with ten separate, but interconnected, layers. The center of the retina is the MACULA. The macula is responsible for allowing detailed vision. The center of the macula is the FOVEA. If the macula is healthy, normal (20/20) vision is possible. If the macula is damaged, detailed vision is lost. The remainder of the retina is responsible for side, or peripheral, vision.
The retinal nerve cells are RODS and CONES. The cones are concentrated toward the center of the retina and are responsible for color vision. The rods are more plentiful in the peripheral retina, and are responsible for "black-and- white" vision in dim lighting.
The retina is prone to a variety of disease conditions. Systemic illnesses such as diabetes and high blood pressure can cause permanent retinal damage. The retina also has its own set of inherent disease conditions, all of which can threaten vision.
PLEASE NOTE: The information contained on this system is not intended to supplant individual professional consultation, but is offered as a community education service. Advice on individual problems should be obtained directly from a professional.
Copyright, 1994. Richard E. Gans, M.D.
Last Modified: August 23, 1996