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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.
About 3.2 billion people, nearly half the world population, are at risk for malaria. In 2015, there are about 214 million malaria cases and an estimated 438,000 malaria deaths.
On average, someone in the United States has a stroke about every 40 seconds. This is about 795,000 people per year.
More than 4.4billion prescriptions were dispensed within the United States in 2016.
Most childhood vaccines are 90–99% effective in preventing disease. Side effects are rarely serious.