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There are 20 feet of blood vessels in each square inch of human skin.
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.
In 1864, the first barbiturate (barbituric acid) was synthesized.
Multiple sclerosis is a condition wherein the body's nervous system is weakened by an autoimmune reaction that attacks the myelin sheaths of neurons.
On average, someone in the United States has a stroke about every 40 seconds. This is about 795,000 people per year.