who invented bifocals

Bifocals were generally invented by Benjamin Franklin. He is credited with sawing his lenses in half so that he could use one part for seeing things at a distance and the other for reading, an invention that likely dates back to the 18th century. Although there is some historical debate and evidence suggesting that others may have preceded him, Franklin is among the first known people to wear bifocal lenses and is often credited with their invention. The term "bifocals" was coined later in 1824 by John Isaac Hawkins, who credited Benjamin Franklin for the invention.