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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.
An identified risk factor for osteoporosis is the intake of excessive amounts of vitamin A. Dietary intake of approximately double the recommended daily amount of vitamin A, by women, has been shown to reduce bone mineral density and increase the chances for hip fractures compared with women who consumed the recommended daily amount (or less) of vitamin A.
Oliver Wendell Holmes is credited with introducing the words "anesthesia" and "anesthetic" into the English language in 1846.
Drying your hands with a paper towel will reduce the bacterial count on your hands by 45–60%.
Malaria was not eliminated in the United States until 1951. The term eliminated means that no new cases arise in a country for 3 years.