Bifocals are the simple and ingenious invention of Benjamin Franklin. Initially created for his personal use, “The Ben Franklin Bifocals” are considered up to now one of the breakthroughs in optics.

Historical records dated back to the late 18th century note Franklin’s extensive usage of a unique type of glasses -with lenses cut though the middle that he would wear all the time. The cut through the middle represents the line between the two types of lenses Franklin combined in order to create a lens that will correct both long distance and near distance vision.

The bifocal lens is made up of a long distance lens, a less convex lens located on the upper side and a near distance lens, a more convex lens located on the lower side. This unique setting gave the ability for the glasses or also known as “spectacles” at that time to help Franklin see both at near distances and far distances. Their valuable features were highlighted by President Thomas Jefferson in one of his private letters where he refers to Franklin’s invention as “a great convenience”.

From the early Ben Franklin bifocals, the technology advanced, allowing for various types of visual impairments to be accommodated through multi focus lenses or also known as multifocals. These types of multifocal lenses adjust not only long distance and near distance vision but will be able to correct also various intermediate distances.

Helping hundreds of millions of people every year, bifocals have now evolved from the weird spectacles to wide used corrective visual mechanisms allowing people to enjoy their life with a perfect vision!