How much did the bifocals cost in 1784?

In 1784, Benjamin Franklin invented bifocals, which were eyeglasses with lenses that could correct both near and far vision. The exact cost of bifocals in 1784 would have varied based on factors such as the materials used, the craftsmanship involved, and the region in which they were purchased. However, historical records suggest that bifocals during that time period could have cost anywhere from a few dollars to several pounds, depending on these variables.