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Did you know?
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.
Did you know?
The familiar sounds of your heart are made by the heart's valves as they open and close.
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Multiple experimental evidences have confirmed that at the molecular level, cancer is caused by lesions in cellular DNA.
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Blood in the urine can be a sign of a kidney stone, glomerulonephritis, or other kidney problems.
Did you know?
The human body produces and destroys 15 million blood cells every second.