On May 23, 1785, Ben Franklin wrote from France to a friend of his, "I have only to move my eyes up and down as I want to see distinctly far and near." Old Ben was describing his latest invention, bifocal glasses. His glasses consisted of a frame with lenses in two parts, each with different focusing powers. Eyeglass frames had been invented in London in 1727.
Not many citizens in the colonies wore glasses of any sort, as they cost about $100.