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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 more nerve cells in one human brain than there are stars in the Milky Way.
Although puberty usually occurs in the early teenage years, the world's youngest parents were two Chinese children who had their first baby when they were 8 and 9 years of age.
Cucumber slices relieve headaches by tightening blood vessels, reducing blood flow to the area, and relieving pressure.
Most childhood vaccines are 90–99% effective in preventing disease. Side effects are rarely serious.