Age related macular degeneration is caused when part of the retina deteriorates.  This condition affects the macula and, therefore, central vision.  Central vision is what you see in front of you as opposed to pheripheral (at the side) vision.  Macular degeneration is the leading cause of legal blindness in people older than 55 in the US.  There are two types:

1. Dry form (more common) - results in a gradual blurring of central vision.  Single or multiple, small, round yellow-white spots called drusen are the key identifiers for the dry type. 

2. Wet form - results in vision distortion in one eye and may affect the other eye later.  Vision loss may be more rapid in the wet form of Mcaular Degeneration.

Symptoms of age related macular degeneration include the following:

1. Blurred or decreased central vision (close-up and distance).
2. Blind spots. 
3. Straight lines appear bent or irregular.  Object appear a different color or shape in each eye.

Research conducted by the National Institute of Health and the National Eye Institute found that people with moderate to advanced age-related macular degeneration were shown to have a significant improvement with regard to disease progression and preservation as a result of taking dietary supplements high in antioxidants and zinc.  Medication and treatment includes Pegaptanib, Bevacizumab, and Ranibizumab. 
People rarely lose all their vision from macular degeneration.  They may have poor central vision but are still able to carry out many normal daily activities.