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Author Question: Describe the rhythm method of birth control.What are some advantages and disadvantages of this ... (Read 45 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.
Vaccines prevent between 2.5 and 4 million deaths every year.
Human kidneys will clean about 1 million gallons of blood in an average lifetime.
On average, someone in the United States has a stroke about every 40 seconds. This is about 795,000 people per year.
Ether was used widely for surgeries but became less popular because of its flammability and its tendency to cause vomiting. In England, it was quickly replaced by chloroform, but this agent caused many deaths and lost popularity.