Although you may not hear about it as much as cataracts and retinal detachments, age-related macular degeneration (AMD) is the leading cause of severe vision loss in people over 50. AMD affects the small part of the retina (macula) that is responsible for our central vision. AMD can make it difficult or impossible for patients to perform routine activities such as reading and driving.

Macular degeneration is damage or breakdown of the macula of the eye. The macula is a small area at the back of the eye that allows us to see fine details clearly. When the macula doesn't function correctly, we experience blurriness or darkness in the center of our vision. Macular degeneration affects both distance and close vision, and can make some activities like threading a needle or reading difficult or impossible. Although macular degeneration reduces vision in the central part of the retina, it does not affect the eye's side, or peripheral, vision. For example, you could see the outline of a clock but not be able to tell what time it is. Macular degeneration alone does not result in total blindness. People continue to have some useful vision and are able to take care of themselves.

Many older people develop macular degeneration as part of the body's natural aging process.

The two most common types of age-related macular degeneration are "dry" (atrophic) and "wet" (exudative). Most people have "dry" macular degeneration. It is caused by aging and thinning of the tissues of the macula. Vision loss is usually gradual. Studies suggest that dry AMD is caused when white-yellow fatty deposits accumulate under retinal tissue. “Wet” macular degeneration results when abnormal blood vessels form at the back of the eye. These new blood vessels leak fluid or blood and blur central vision. Vision loss may be rapid and severe. "Wet" macular degeneration accounts for about 10% of all cases of macular degeneration but 90% of severe vision loss caused by macular degeneration.

Macular degeneration can cause different symptoms in different people. The condition may be hardly noticeable in its early stages. Sometimes only one eye loses vision while the other eye continues to see well for many years. But when both eyes are affected, the loss of central vision may be noticed more quickly. A few common ways in which vision loss is detected is if words on a page look blurred, a dark or empty area appears in the center of vision, or straight lines look distorted.