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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.
There are approximately 3 million unintended pregnancies in the United States each year.
Bacteria have flourished on the earth for over three billion years. They were the first life forms on the planet.
The training of an anesthesiologist typically requires four years of college, 4 years of medical school, 1 year of internship, and 3 years of residency.
Human stomach acid is strong enough to dissolve small pieces of metal such as razor blades or staples.