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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 most destructive flu epidemic of all times in recorded history occurred in 1918, with approximately 20 million deaths worldwide.
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In 1864, the first barbiturate (barbituric acid) was synthesized.
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Aspirin is the most widely used drug in the world. It has even been recognized as such by the Guinness Book of World Records.
Did you know?
If all the neurons in the human body were lined up, they would stretch more than 600 miles.