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Cataract is clouding of the eye lens that reduces the amount of incoming light and results in deteriorating vision. Cataract is often described as being similar to looking through a waterfall or waxed paper. Daily functions such as reading or driving a car may become difficult or impossible. Eyeglass prescriptions may require frequent changes. An estimated 200 million people worldwide have cataracts.
Minor lens opacities at birth may never progress to cataract in adulthood, while others progress to a degree requiring surgery or causing blindness. Many factors influence vision and cataract development including age, nutrition, heredity, medications, toxins, health habits, sunlight exposure, and head trauma. Hypertension, kidney disease, diabetes, or direct trauma to the eye can also cause cataract.
Today, cataract surgery is a common surgery in the United States, with over 1.5 million surgeries done yearly. Annual costs associated with cataract treatment are estimated to be over $3.4 billion.1,2 Cataract surgery costs Medicare more than any other medical procedure: 60% who initially qualify for Medicare already have cataracts.3
There are three main types of cataracts. The most common is nuclear cataract. Nuclear cataract occurs when proteins of the nucleus (center) degenerate and darken, causing light to scatter. The second most common type, cortical cataract, occurs in the cortex (or periphery) of the lens. Cortical cataract forms when the order of fibers in the cortex is disturbed and the gaps fill with water and debris, thus altering the pathophysiology of light by scattering and/or absorbing it. The least common type affects the back of the lens and is called posterior subcapsular cataract.
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