Cataracts occur when there is a clouding of the lens of the eye. While there are several different types of cataracts, age-related cataracts are the most common. Possible symptoms of a cataract include blurry vision, double vision, and frequent prescription changes for eyeglasses or contact lenses; however, other conditions can cause these symptoms. If you have any of these symptoms, you should see an eye care professional. In most cases, the only available treatment for a cataract involves surgery. However, it is a very common procedure -- over 1 million cataract surgeries are performed each year in the United States.