|
|
On average, someone in the United States has a stroke about every 40 seconds. This is about 795,000 people per year.
Sperm cells are so tiny that 400 to 500 million (400,000,000–500,000,000) of them fit onto 1 tsp.
After a vasectomy, it takes about 12 ejaculations to clear out sperm that were already beyond the blocked area.
A cataract is a clouding of the eyes' natural lens. As we age, some clouding of the lens may occur. The first sign of a cataract is usually blurry vision. Although glasses and other visual aids may at first help a person with cataracts, surgery may become inevitable. Cataract surgery is very successful in restoring vision, and it is the most frequently performed surgery in the United States.
Human kidneys will clean about 1 million gallons of blood in an average lifetime.