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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Illicit drug use costs the United States approximately $181 billion every year.
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Chronic necrotizing aspergillosis has a slowly progressive process that, unlike invasive aspergillosis, does not spread to other organ systems or the blood vessels. It most often affects middle-aged and elderly individuals, spreading to surrounding tissue in the lungs. The disease often does not respond to conventionally successful treatments, and requires individualized therapies in order to keep it from becoming life-threatening.
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The types of cancer that alpha interferons are used to treat include hairy cell leukemia, melanoma, follicular non-Hodgkin's lymphoma, and AIDS-related Kaposi's sarcoma.
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The average human gut is home to perhaps 500 to 1,000 different species of bacteria.
