Visual disabilities can range from moderate to severe, including low vision all the way to blindness. Someone who has a visual disabilities is considered to need some type of a visual correction aid. There are several things that can cause vision loss and lead to visual disabilities. Some of these causes include:

• Macular degeneration - This is leading cause of vision loss in people over 50. This type of vision loss affects a person central vision since the center of the retina, the macula, and degenerates and causes visual disabilities. A person with this type of vision loss will have problems reading, driving, and doing small handwork. There are two types of macular degeneration: the “dry” form and the “wet” form. The dry form of this disease is a slow process of this disease and is the most common occurrence. The wet form of this disease will rarely cause blindness.
• Diabetic retinopathy - These types of visual disabilities are caused by diabetes, both Type I and II. Vision loss occurs when the blood vessels in the retina are damaged by diabetes. If detected early enough surgical procedures such as laser surgery can treat diabetic retinopathy. If not detected early enough blindness will occur resulting in visual disabilities.
• Glaucoma - Glaucoma is the buildup of pressure within the eye for several reasons. Once the optic nerve is damaged the end result is lost or distorted peripheral vision. Although there is no cure for glaucoma early detection can slow or halt some of the vision loss.
• Cataracts - A cataract is the clouding over of the eye by the eye’s natural lens. This allows less light to flow through to the eye. This is a common medical condition in people over 55 and can be successfully treated by surgery.
  

Approximately 85% of macular degeneration cases are the "dry" form, characterized by a slow and gradual breakdown of the macular cells. If blood vessels grow behind the macula in an effort to provide more oxygen and they burst and bleed, this is referred to as the "wet" form. It is experienced by about 15% of macular degeneration patients. On a positive note, the wet form almost never results in total blindness. It does, however, cause severe vision loss, sometimes resulting in legal blindness (20/200 or worse in both eyes).