Which founding father is credited with inventing bifocal glasses?

• A. George Washington
• B. Thomas Jefferson
• C. Alexander Hamilton
• D. Benjamin Franklin

Answer: (D)

The idea being tested is recognizing who first created a practical way to correct both near and distant vision in one pair of glasses. Benjamin Franklin is the founding father linked to this invention. He found it tedious to switch between separate pairs for reading and for distance, so he devised glasses that combined two lenses in one frame: the part at the top tuned for distance and the part at the bottom for reading. This simple split—two focal lengths in one lens—made it possible to see clearly at different distances without swapping spectacles, and the design came to be known as bifocals. Franklin’s approach was practical, widely adopted, and laid the groundwork for how people think about vision correction in a single, versatile pair. The other figures aren’t associated with inventing this particular device.