Macular degeneration affects a structure in the eye called the macula, the small, center portion of the retina. Although it usually doesn't cause total blindness, macular degeneration affects central vision and can cause significant vision loss.
The retina is the inner layer of the eye that contains nerves and receptors that gather light signals and communicate them to the optic nerve and then to the brain. The macula is the portion of the retina that permits a person to see colors and details. Macular degeneration causes deterioration of the macula. This condition often develops as people age, and is one of the leading causes of vision loss in people over the age of 60.