The macula is where light focuses after passing through the cornea, pupil, and lens. The macula's function is to sense light, and create impulses that are sent through the optic nerve to the brain the macula is responsible for central vision, and your ability to see color, and fine detail when you look directly at an object. Macular degeneration is a disease that affects the central vision. It is the most common cause of vision loss among people over age 60. Macular degeneration generally takes two forms. Dry, age-related macular degeneration affects 90% of those with the disease. The earliest sign that macular degeneration is beginning is the development of tiny areas in the macula called drusen. This form occurs when the tissue of the macula thins over time. Since the dry form is simply a matter of the macula wearing out with age the loss of central vision tends to be gradual over the years. This form of the disease is more prevalent, but less serious. Wet age-related macular degeneration affects 10% of those with the disease. In this form, abnormal blood vessels grow underneath the retina. These vessels may leak, and cause scarring, and loss of central vision if any of this damage occurs within the macula, serious and rapid deterioration of the person's Central vision can result. This form accounts for 90% of the most serious loss of vision cases. The dry form of this disease may convert to a wet form at any time. The wet form usually occurs in people who already have the dry form.