This causes problems with glare from lamps or the sun and vision gradually becomes dull and fuzzy, even in daylight. Most of the time, cataracts occur in both eyes, but only one eye may be affected. If they form in both eyes, one eye can be worse than the other, because each cataract develops at a different rate. During the time cataracts are forming, vision can be helped with frequent changes in eyeglass prescriptions. Although there are several causes of cataracts, senile cataracts are the most common form.
Cataracts can accompany aging, probably due to changes in the chemical state of lens proteins.
About half of Americans ages 65 to 74 have cataracts. About 70 percent of those over 75 have this condition. Traumatic cataracts develop after a foreign body enters the lens capsule with enough force to cause specific damage. Ionizing radiation or infrared rays can also lead to this type of cataract. Toxic cataracts can result from medicine or chemical toxicity.