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.
It is caused by aging and thinning of the tissues of the macula. Vision loss is usually gradual. It 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.