Cataract: single leading cause of blindness

Cataract is the single leading cause of blindness worldwide. A cataract is an imperfection in the clarity or a clouding of the lens of the eye.

Depending on the degree of cloudiness, cataract can cause a little blur in vision to near total loss of vision. It will be experienced by a majority of people who live to an old age. In children, some cataracts are present at birth and other develops with metabolic or systemic abnormalities.

Luckily, the disorder can usually be corrected by surgical removal of the clouded lens and if possible replacement of the old lens with a synthetic one in order to restore proper sight.

Eden 1978 defines three types of cataracts:
*Senile cataracts due to aging
*Secondary cataracts result from some other trauma or disease or excessive radiation and side effects of drugs
*Congenital cataracts Cataract classifications based on stage include: immature, mature, hypermature and morgagnian cataract.

While immature cataracts still have some transparent protein left, mature cataracts are often easily recognizable because all proteins have become opaque. Hypermature cataracts progress so far that their proteins become liquid.
Cataract: single leading cause of blindness

Macular degeneration

Macular degeneration also known as age-related macular degeneration (AMD or ARMD) is the most common cause of legal blindness in people over 50 in the United States. There is no medical treatment for dry AMD and no cure.

Macular degeneration is caused by cumulative damage to the macula, the center of the retina, where both ganglion cells and cones are present at very high densities. It starts as a blurred spot in the center of what you see. As the degeneration spreads, vision shrinks.

Free radicals generated by sunlight, cigarette smoke, air pollution, infection, and metabolism cause much of this damage.

In the past several years, researchers have found genes associated with Stargardt disease both wet and dry AMD and retinitis pigmentosa. May eye diseases, including retinitis pigmentosa, familial exultative maculopathy, Sticker’s syndrome, and stationery night blindness, have a genetic component.
Macular degeneration