|
|
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.
As the western states of America were settled, pioneers often had to drink rancid water from ponds and other sources. This often resulted in chronic diarrhea, causing many cases of dehydration and death that could have been avoided if clean water had been available.
If all the neurons in the human body were lined up, they would stretch more than 600 miles.
After a vasectomy, it takes about 12 ejaculations to clear out sperm that were already beyond the blocked area.
Human stomach acid is strong enough to dissolve small pieces of metal such as razor blades or staples.


