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.
A cataract can occur in either or both eyes. It cannot spread from one eye to the other.
A team of researchers from the Agency for Science, Technology and Research's (A*STAR) Genome Institute of Singapore (GIS) and Bioprocessing Technology Institute (BTI), as well as Singapore Eye Research Institute (SERI), have identified a genetic mutation (functionally defective CYP39A1 gene) associated with exfoliation syndrome, the most common cause of glaucoma.
Cataracts are the most prevalent eye disease in humans. But despite this fact, the actual processes that lead to this disease are not entirely known.
The lens of the eye is an unusual organ. Unlike most of the body's organs, blood vessels don't reach the lens. If they did, they'd obscure our vision and we wouldn't be able to see. The lack of vasculature led scientists to believe immune cells, which travel via the bloodstream, couldn't get to this part of the body either.