The crystalline lens of the eye, which is crystal-clear when healthy, gets blurry and becomes opaque. This opacity of the lens is also called "cataract", if the vision of the affected person is restricted.
Almost 90% of all cataracts are age related cataracts, also called "katarakta senilis". In the German-speaking world cataract surgeries are more than 500,000.
There are no preventive measure available, and as this disorder does not cause any pain the opacity at the periphery of the lens may exist for years unnoticed by the affected person. Only with the progress of the disease the loss of eyesight gets evident. Vision gets blurry and distorted and the world seems to be completely gray. The only possible treatment is the cataract surgery (surgical measures); during this operation the opaque lens is removed and usually replaced with a plastic lens. If it is not possible to implant an artificial lens, the missing lens can be compensated by an optical correction with the help of thick glasses, the so-called cataract lenses, or with contact lenses. There is no medical treatment of cataract. About twenty to thirty percent of the patients who had a surgery may develop a secondary cataract.
Author: J. Land