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Astigmatism is the most common vision problem. It may accompany nearsightedness or farsightedness. It is usually caused by an irregularly shaped cornea, but sometimes it is the result of an irregularly shaped lens. Either type can be corrected by eyeglasses, contact lenses, or refractive surgery.
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The immune system needs 9.5 hours of sleep in total darkness to recharge completely.
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Allergies play a major part in the health of children. The most prevalent childhood allergies are milk, egg, soy, wheat, peanuts, tree nuts, and seafood.
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Between 1999 and 2012, American adults with high total cholesterol decreased from 18.3% to 12.9%
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There are 20 feet of blood vessels in each square inch of human skin.