A cataract is a clouding of the eye's lens. It makes it hard for you to see. A cataract won't spread from one eye to the other, but many people get them in both eyes.
As the cataract grows and gets cloudier, it may become harder to read and do other tasks. Many people are not aware that their eyesight is blurry because cataracts grow slowly over time.
The cause of this clouding is not known. Many things can lead to cataracts forming, such as:
- Aging
- Smoking
- Drinking too much alcohol
- Health problems, such as diabetes
- Some infections
- Eye disease, or injury or burns of the eye
- Exposure to radiation, toxins, or some medicines
- Taking steroid medicines for a long time
- Too much time spent in the sun
- Problems found at birth
Last reviewed December 2018 by EBSCO Medical Review Board
James P. Cornell, MD
Last Updated: 2/14/2019