|
|
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.
In most cases, kidneys can recover from almost complete loss of function, such as in acute kidney (renal) failure.
The modern decimal position system was the invention of the Hindus (around 800 AD), involving the placing of numerals to indicate their value (units, tens, hundreds, and so on).
After a vasectomy, it takes about 12 ejaculations to clear out sperm that were already beyond the blocked area.
More than 4.4billion prescriptions were dispensed within the United States in 2016.