The decline or change of the central area of the retina of the eye, a part that is important in the visualization of fine details: Macular degeneration is the leading cause of visual impairment in people over the age of 50, and it can lead to the loss of the central vision, making it difficult to read or to do fine work; such as, threading a needle.

Usually macular degeneration doesn't cause blindness because only the central area of vision is affected.

Injury that causes macula degeneration usually decreases the ability to see straight ahead clearly and sometimes it makes it difficult to read, to drive, or to perform other daily activities that require good central vision.

Macular degeneration normally affects both eyes, either simultaneously or one eye then the other one later.

Any retrogressive change associated with the abnormal production of mucus.