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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?
Multiple experimental evidences have confirmed that at the molecular level, cancer is caused by lesions in cellular DNA.
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Oliver Wendell Holmes is credited with introducing the words "anesthesia" and "anesthetic" into the English language in 1846.
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Most childhood vaccines are 90–99% effective in preventing disease. Side effects are rarely serious.
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Thyroid conditions cause a higher risk of fibromyalgia and chronic fatigue syndrome.