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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?
Human stomach acid is strong enough to dissolve small pieces of metal such as razor blades or staples.
Did you know?
It is important to read food labels and choose foods with low cholesterol and saturated trans fat. You should limit saturated fat to no higher than 6% of daily calories.
Did you know?
Vaccines prevent between 2.5 and 4 million deaths every year.
Did you know?
The familiar sounds of your heart are made by the heart's valves as they open and close.