Astigmatism - an vision defect causing lines in some directions to be focused less sharply than lines in other directions. The normal lens allows light to reach the retina for clear vision.
Cataracts reduce vision, just as a dirty windshield diminishes a driver's view of the road.
The number one cause of blindness in the world is cataracts. Although factors such as nutrition and genetics play a role in cataract formation, UV exposure is primarily responsible. The clouding of the lens is irreversible, and once the cataracts begin to impair daily activities, the only treatment available is surgical removal. The good news is that cataract surgery is relatively uncomplicated, and has a very high success rate. The tear film is an important source of eye nutrition, waste removal, and antibacterial action.