Bifocal Glasses

The invention of Bifocal lens is credited to the great American statesman and inventor Benjamin Franklin. The story of this invention dates back to 1784 at a time when Sir Benjamin Franklin was getting pale and old. The strength of his eyes was completely deteriorated. He was tired switching between close and distant lens and therefore he devised the bifocal lens. Bifocal glasses are glasses with two distinct optical powers. Each lens is divided into two parts- the upper portion of lens is a convex lens for viewing distant objects and the lower portion is affixed with a concave lens for close viewing, such as for reading purposes. Though Benjamin Franklin was the inventor of bifocal but the method of fusing the lenses together was developed by Louis de Wecker. … Read entire article »