What causes cataracts?
We know that some diseases are associated with cataracts, such as diabetes, and that some drugs can cause cataracts, such as steroids or prednisone. Exposure to ultraviolet light causes a kind of cataract. But in general, we see an increased incidence of cataracts as we age. So it's one of those things that happens to almost everybody if they live long enough.
Can cataracts eventually cause blindness?
Cataracts gradually cause a loss of vision. If cataracts are not treated, vision can get so poor that you become legally blind, meaning you see light, but no images, no detail. Fortunately, in the United States, most people seek care before they get that bad.
How do you know that you have a cataract?
The symptoms of cataracts are typically a change in vision. Maybe you can't read anymore. Maybe you're having trouble driving. Another symptom can be glare, particularly when driving at night with headlights coming toward you, so you may feel you're not seeing as well as you used to when you drove at night. Some people also complain that colors don't seem as rich as they used to be. This change of vision isn't improved with glasses. So if you change your glasses and you still can't see well, the most common cause is cataracts.