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Author Question: What kind of compound is urea? (Read 17 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.
According to the American College of Allergy, Asthma & Immunology, more than 50 million Americans have some kind of food allergy. Food allergies affect between 4 and 6% of children, and 4% of adults, according to the CDC. The most common food allergies include shellfish, peanuts, walnuts, fish, eggs, milk, and soy.
Although puberty usually occurs in the early teenage years, the world's youngest parents were two Chinese children who had their first baby when they were 8 and 9 years of age.
Asthma cases in Americans are about 75% higher today than they were in 1980.
In 1835 it was discovered that a disease of silkworms known as muscardine could be transferred from one silkworm to another, and was caused by a fungus.