The most common cause of cataracts is advancing age and the passage of time. While the origin and development of age-related cataracts is not yet completely understood, statistics suggest that the longer we live, the more likely it is that the lens will become less clear and flexible. According to data from the Beaver Dam Eye Study, 38.8% of men and 45.9% of women older than 74 have visually significant cataracts.

In addition to the aging process, cataracts can also be caused by any of the following:

• Medication: Corticosteroids to reduce inflammation (such as prednisone)
• Physical injury or trauma: A blow to the eye, a cut or puncture, chemical burns, or electric shock
• Radiation: Long-term exposure to ultraviolet radiation from the sun (both UVA and UVB)
• Poor nutrition: Diets that are deficient in antioxidants, such as beta-carotene (vitamin A), selenium, and vitamins C and E
• Smoking and second-hand smoke: Individuals who smoke 20 or more cigarettes a day have twice the risk of nonsmokers for developing cataracts.
• Systemic diseases, such as diabetes and diabetic retinopathy;
• Eye diseases, such as uveitis, which is an inflammatory process that affects the interior of the eye;
• Cataracts can also be inherited or congenital (from birth)