Causes of Blindness & Low Vision

Blindness and low vision have a variety of causes that range from communicable diseases to genetic disorders. Other factors like ingesting dangerous substances and intentional damage also account for a number of the people in the world who are blind. A large number of the situations that cause these problems can be prevented or fixed with better health care options, especially in the developing world.

Diseases

• According to the World Health Organization, the majority of blind people around the world suffered vision loss due to preventative and treatable diseases or malnutrition. Nearly 50 percent of all blindness is caused by cataracts, while glaucoma and macular degeneration account for around 20 percent.

Abnormalities

• Injury to the eye is the leading cause of blindness in the United States, according to the American Foundation for the Blind. Damage to the occipital lobe and the optic nerve can cause blindness and vision loss in one or both eyes.

Genetic Defects

• A number of genetic disorders also account for blindness and vision loss. Albinism, Leber's congenital amaurosis and Bardet-Biedl syndrome are the primary culprits. Although human genome mapping has identified certain DNA strands, genetic therapy has thus far been unable to cure these problems.

Chemical Damage

• Certain chemicals, when ingested, can cause blindness. The most common example is methanol, which is mildly toxic, but often used as a substitute for alcohol. This breaks down into formaldehyde and formic acid, which causes blindness in humans.

Intentional Blindness

• In cases of punishment or torture, blindness in one or both eyes has been used for centuries as a form of justice or revenge. There have also been reports of people blinding themselves for religious or cultural reasons.