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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.
The first documented use of surgical anesthesia in the United States was in Connecticut in 1844.
More than 20 million Americans cite use of marijuana within the past 30 days, according to the National Survey on Drug Use and Health (NSDUH). More than 8 million admit to using it almost every day.
Certain rare plants containing cyanide include apricot pits and a type of potato called cassava. Fortunately, only chronic or massive ingestion of any of these plants can lead to serious poisoning.
Although puberty usually occurs in the early teenage years, the world's youngest parents were two Chinese children who had their first baby when they were 8 and 9 years of age.