A cataract is a clouding of the lens of the eye. The lens is responsible for focusing light onto the back of the eye, which is then translated into images for the brain to process. When a cataract forms, the lens becomes clouded, making it more difficult for light to pass through. This can lead to vision problems such as blurred vision, double vision, or light sensitivity. Cataracts can also cause colors to appear faded or yellow.
The most common type of cataract is called a nuclear cataract, which develops in the center of the lens and typically progresses slowly. Another type of cataract is called a cortical cataract, which develops in the outer edges of the lens and tends to move more quickly. In rare cases, a cataract may be caused by trauma or an underlying medical condition.