The invention of the bifocals was one of the most important inventions of the 1700s. They have changed the lives of both children and adults that have issues with their eyesight. They rid people of eyestrain and headaches. Also, bifocals rid people of the inconvenience caused by having to shift from one pair of glasses to the other. Bifocals also allowed for more types of glasses to be developed.
As Benjamin Franklin grew older, his vision worsened. He became both far-sighted and near-sighted and the constant switching of his glasses frustrated him so much that he decided to solve this problem. He invented a pair of glasses that incorporated both lenses into one frame called bifocals. “Bifocals are a type of prescription eyeglasses designed for people who need both near and farsighted vision correction. Benjamin Franklin developed the first pair of bifocals in August 1784” (Beam "What Are Bifocals?"). With these two-lense bifocals one could look through the upper half to see far away and the lower half for seeing closer things. Many historians question who invented the bifocals although, due to letters written by Benjamin Franklin to his friend George Whatley, it is a known fact that Franklin was indeed the true inventor of the bifocals (The Electric Franklin "Benjamin Franklin's Inventions").
They are generally used by people over forty years old (Heiting "Bifocals and Trifocals for Vision Over 40"). Single vision glasses and bifocals are very different types of glasses because they only help people with nearsightedness. This is why bifocals are very useful because they are two pairs of lenses within one frame. Bifocals are generally associated with adults, but there are many cases in which children too require bifocals. In some cases, due to over focussing when a child has not developed sufficient control over their focusing systems, a child may experience headaches and eyestrain (Barton "Bifocals For Children"). Bifocals have solved this problem for both children and adults. With bifocals there is no strain or hassle. If not children with difficulty controlling their focus systems,generally people over forty need bifocals because at that age their eye muscles have been tired out from many years of use.
A different, more advanced prototype that Franklin’s was developed later by Louis de Wecker in the 19th century. He used a more cutting-edge technique of making bifocals that is used today. “The mounting of two half lenses into a single frame led to a number of early complications and rendered such spectacles quite fragile” ("Forcaza Lens "). This realization led Louis de Wecker to invent bifocals that were more durable. “A method for fusing the sections of the lenses together was developed by Louis de Wecker at the end of the 19th century...” ("Forcaza Lens "). This method proved to be much more reliable. Today, bifocals have a much smaller portion of lense used for farsightedness.
As bifocals evolved, they led to the...