Aging is the most common cause of cataracts, which most often occur in people over 50 years of age. This is believed to be due to an accumulation of free radical damage to the lens over time. Research has confirmed this by showing that a diet high in antioxidants can reduce the risk of developing caracts.
Some people may develop cataracts due to steroid use, diabetes or following eye injury. It is belived that this process also involves free radical destruction.