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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?
After a vasectomy, it takes about 12 ejaculations to clear out sperm that were already beyond the blocked area.
Did you know?
Cytomegalovirus affects nearly the same amount of newborns every year as Down syndrome.
Did you know?
About 100 new prescription or over-the-counter drugs come into the U.S. market every year.
Did you know?
The average human gut is home to perhaps 500 to 1,000 different species of bacteria.