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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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In 1864, the first barbiturate (barbituric acid) was synthesized.
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Parkinson's disease is both chronic and progressive. This means that it persists over a long period of time and that its symptoms grow worse over time.
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The familiar sounds of your heart are made by the heart's valves as they open and close.
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Cucumber slices relieve headaches by tightening blood vessels, reducing blood flow to the area, and relieving pressure.