Who invented bifocal glass

Through his writings he helped form the anti-British opposition among the colonies. As a writer, Franklin placed a strain on his eyesight. To help ease this strain, Franklin invented glasses that could be used in regular life and as an aid to reading. With this invention, the first bi-focal glasses were invented. One of the biggest misconceptions that people have is that Benjamin Franklin invented electricity.

This is incorrect. The truth is Franklin was credited with inventing the lightning rod, which was a device used to capture the power of lightning. Sir Benjamin Franklin was born on 17th January and died on 17th April at the age of He was also a leading author and printer.

Besides these, he was also a political therapist, a politician, an inventor, a scientist, a postmaster, a diplomat, a freemason, a humorist, a postmaster, and also a statesman. He was very wary of switching between lenses that he used for his farsightedness eye problem and nearsightedness eye problem. That instigated him to create the bifocal lens. The up-gradation that has evolved since years of this invention is evident now.

But when it was first discovered, the scenario was something different. This would have made him likely to have benefited from bifocals by the time he arrived in London in Before leaving America for the first time Franklin had clearly had an interest in optical developments.

He imported vision aids and advertised 'spectacles of several sorts' in the Pennsylvania Gazette. Our knowlege that he was involved in the supply of spectacles in his early adult life may cause us to consider that he may well have had the interest to experiment with bifocals at an earlier date.

Yet the only portrait of Franklin in which he is depicted wearing bifocals is one by Charles Willson Peale, dated , when the old man was aged 81 and living once again in Pennsylvania. This does at least suggest that we would be right to say that Franklin introduced bifocals to America.

Wider public awareness of the invention only came about in the early s, following Franklin's death. During this period several authors published the Whatley letter, thereby cementing in the public mind the link between bifocals and Franklin. Peale, having painted Franklin wearing bifocals, is known to have made his own pair in and may have been responsible for introducing the concept to the first US optician, John McAllister, some time after The idea for bifocal spectacles, attributed by some people to Franklin in both Britain and the US, though never patented by him or anyone else soon led to further developments.

The use of hinged supplementary visors to hold reading lenses was patented in London by John Richardson in By Isaac Schnaitman, a German immigrant to Philadelphia, had taken out a patent on one-piece lenses with both distance and reading portions ground on to one piece of glass. Another claimant to the title? Benjamin West , an American artist, originally from Philadelphia, was a natural friend for Franklin in London.

He would later become President of the Royal Academy from West is known to have been an early wearer of 'divided glasses' or bifocals, possibly before , but probably not before Franklin. It is also suitable for people who develop a combination of far sightedness and nearsightedness. The lenses in the lower half are for nearsightedness and lenses in the upper part are for farsightedness correction.

They can also be used to correct astigmatism present in combination with any other refractive defects. The story of invention of bifocal glasses or lens dates back to when sight of Sir Benjamin Franklin was deteriorated.

He was tired switching between lenses for far and near sightedness. So he created the bifocal lens. At the beginning two lenses were combined directly resulting in a sharp switch between upper and lower lenses.

At the end of 19th century Louis de Wecker resolved this problem by fusing the sections of lenses together. Peter Williams who invented trifocal lenses coined the term bifocals and credited Benjamin Franklin in Every coin has two sides.