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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.
The Babylonians wrote numbers in a system that used 60 as the base value rather than the number 10. They did not have a symbol for "zero."
Each year in the United States, there are approximately six million pregnancies. This means that at any one time, about 4% of women in the United States are pregnant.
By definition, when a medication is administered intravenously, its bioavailability is 100%.
Asthma attacks and symptoms usually get started by specific triggers (such as viruses, allergies, gases, and air particles). You should talk to your doctor about these triggers and find ways to avoid or get rid of them.