• What Causes Cataracts?

    Written By: Kierstan Boyd
    Reviewed By: Elena M Jimenez MD
    Nov. 15, 2016

    In the normal human eye, light rays travel into the eye through the pupil. They pass through the clear lens and focus onto the retina.

    In an eye with a cataract, light scatters throughout the eye instead of focusing precisely on the retina.

    Cataract as part of aging

    Though there are other risk factors for cataracts, aging is the most common cause. This is due to normal eye changes that happen after around age 40. That is when normal proteins in the lens start to break down. This is what causes the lens to get cloudy. People over age 60 usually start to have some clouding of their lenses. However, vision problems may not happen until years later.

    Most age-related cataracts develop gradually. Other cataracts can develop more quickly, such as those in younger people or those in people with diabetes. Doctors cannot predict how quickly a person’s cataract will develop.

    You may be able to slow down your development of cataracts.

    Protecting your eyes from sunlight is the best way to do this. Wear sunglasses that screen out the sun’s ultraviolet (UV) light rays. You may also wear regular eyeglasses that have a clear, anti-UV coating. Talk with your eye doctor to learn more.

    Who Is at Risk for Cataracts?

    Besides aging, other cataract risk factors include:

    • having parents, brothers, sisters, or other family members who have cataracts
    • having certain medical problems, such as diabetes
    • having had an eye injury, eye surgery, or radiation treatments on your upper body
    • having spent a lot of time in the sun, especially without sunglasses that protect your eyes from damaging ultraviolet (UV) rays

    If you have any of these risk factors for cataract, you should schedule an appointment with your ophthalmologist.