The lens is made of mostly water and protein. The protein is arranged in a precise way that keeps the lens clear and allows light to pass through it. But as we age, some of the protein may clump together and start to cloud a small area of the lens. This is a cataract, and over time, it may grow larger and cloud more of the lens, making it harder to see.
Most cataracts occur gradually as we age and don’t become bothersome until after age 55. However, cataracts can also be present at birth (congenital cataracts) or occur at any age as the result of an injury to the eye (traumatic cataracts). Cataracts can also be caused by diseases such as diabetes or can occur as the result of long-term use of certain medications, such as steroids.