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Cataracts and Aging


Updated May 24, 2007



ADAM Medical Encyclopedia
Definition: an eye disorder related to aging that can cause cloudy spots, known as cataracts, to form on the eye.

Cataracts and Aging

Starting in our mid-40s, the proteins within the lens of the eye begin to bind to each other in a process known as cross-linking. These bound proteins become stiffer (which causes difficulty in reading and seeing close objects). If the proteins clump together, a cloudy spot forms, called a cataract. Cataracts become a problem when they interfere with vision.

Causes of Cataracts

Cataracts are caused by a number of factors working together:
  • Free radicals: These highly reactive oxygen molecules bind to proteins within the eye, causing them to lose an electron and bind to other proteins.
  • Sunlight, UV Rays and Radiation: Sunlight contain ultraviolet radiation that causes damage to the lens of the eye, resulting in the formation of cataracts. Cancer patients who undergo radiation treatments are also at elevated risk for cataracts.
  • Smoking: Smoking causes an increase in free radical activity in the body and therefore increases risk for cataracts.
  • Medications: The long-term use of some medications, such as oral steroids, can cause cataracts.
  • Other Eye Disorders: Glaucoma and other eye disorders can place a person at a high risk for cataracts.
  • Diabetes: People with diabetes have a high cataract risk because elevated blood sugar can cause proteins to cross-link.


Nearly all cataracts can be successfully removed through surgery.


The risk of getting cataracts can be decreased by maintaining a healthy lifestyle, which includes managing your blood pressure and blood sugar and getting plenty of antioxidants in your diet.

Back to Aging-Related Eye Disorders


National Institute of Aging. Aging and Your Eyes. Bound for Your Good Health. Pages 69-72.

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