Thursday Open Line


One of the most versatile and gifted people in American history revealed the invention of bifocal eyeglasses this month in 1785. Benjamin Franklin had been using one pair of glasses to read with and another for distant vision. Writing of this from France to an acquaintance, Franklin said he had the two pairs of lenses cut in half and mounted in the same frame. The idea of these split lenses, or bifocals, was slow to be adopted because of the high cost. Among Franklin’s many other inventions were the lightning rod, an efficient wood stove, swim fins, and an odometer. Today, Americans spend close to a billion dollars a year at the nation’s nearly 13,000 optical stores for contact lenses and eyeglasses, including bifocals. You can find more facts about America from the U.S. Census Bureau online at <www.census.gov>.