What Happened in History: Browse Historical Facts on Kudos 365

Ben Franklin reveals his invention of bifocal eyeglasses in a letter, now in the Library of Congress, to his friend George Whatley. Franklin was having problems seeing both up-close and at greater distances and in the prior year, he created a method for placing differently-calibrated lenses into the same frame rather than constantly changing glasses. His new "double spectacles" had pairs of half-lenses arranged in a top-bottom configuration. Franklin commented that all he had to do was but move his eyes up or down, and the proper glass was always ready! Franklin never patented any of his inventions, and wanted to share them freely. More