A cataract is a clouding or loss of transparency of the lens of the eye. Cataracts are most common in old age and arise due to tissue breakdown. There are many causes of cataracts, including aging, trauma or injury to the eye, diabetes, or other conditions. Obesity, smoking, family history of the condition, ultraviolet radiation exposure, previous eye surgery, and high blood pressure are other risk factors for developing cataracts.
Symptoms and signs of cataracts include clouded or blurred vision, vision loss, seeing halos around lights, inability to see at night or in dim light, and sensitivity to light (photophobia) and glare. Associated symptoms can include double vision and fading or perceived yellowing of colors. Cataracts do not cause eye pain.
Causes of cataracts
Age-related changes to the eye's lens are the primary cause of cataracts. Genetics, diabetes, long-term use of steroid medications, eye injuries, and previous eye surgeries may also cause cataracts.
Kasper, D.L., et al., eds. Harrison's Principles of Internal Medicine, 19th Ed. United States: McGraw-Hill Education, 2015.
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