A cataract is a clouding of the lens in the eye that affects vision. Most cataracts are related to aging. Cataracts are very common in older people. By age 80, more than half of all Americans either have a cataract or have had cataract surgery.
CVS is caused by our eyes and brain reacting differently to characters on the screen than they do to printed characters. Our eyes have little problem focusing on most printed material, which is characterized by dense black characters with well-defined edges.
