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Author Question: According to research investigating the effects of child-care programs on children's cognitive ... (Read 20 times) |
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.
The first documented use of surgical anesthesia in the United States was in Connecticut in 1844.
There are over 65,000 known species of protozoa. About 10,000 species are parasitic.
The term bacteria was devised in the 19th century by German biologist Ferdinand Cohn. He based it on the Greek word "bakterion" meaning a small rod or staff. Cohn is considered to be the father of modern bacteriology.
Earwax has antimicrobial properties that reduce the viability of bacteria and fungus in the human ear.