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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?
Between 1999 and 2012, American adults with high total cholesterol decreased from 18.3% to 12.9%
Did you know?
HIV testing reach is still limited. An estimated 40% of people with HIV (more than 14 million) remain undiagnosed and do not know their infection status.
Did you know?
Bacteria have been found alive in a lake buried one half mile under ice in Antarctica.
Did you know?
The horizontal fraction bar was introduced by the Arabs.