Ever wonder how bifocal reading glasses came to be? If you use them on a regular basis you may find it interesting to learn more about how they were developed. I was curious, so I decided to share what I found. Here Bifocal Reading Glasses presents you the History of Bifocals.
Origin of the Eyeglass Lens
The origin of reading bifocals begins with the origin of magnification, which dates all the way back to Egyptian hieroglyphs around 700 BC.
The earliest written record of such magnification appears to be the first century AD when Seneca the Younger, a tutor of Emperor Nero, wrote how small letters could be made more large and clear using a “globe or glass filled with water.” Appropriately, there is written evidence that Emperor Nero’s enjoyment of gladiator games was improved by the use of a vision-correcting lens in the form of an emerald.
Later, many believe corrective lenses of some form were utilized by Abbas Ibn Firnas in the 9th century AD. Abbas Ibn Firnas developed a method to create clear glass. He shaped and polished the glass into rocks of round he called reading stones. The earliest concrete evidence of these sorts of magnifying devices (utilizing a convex lens to magnify an image) seems to be the Book of Optics, published by Alhazen in about 1021.
Translating this vital source of knowledge into Latin during the 12th century led to the earliest eyeglasses as we know them, which were developed around 1284 in Florence, Italy, by the Dominican friar Alessandro della Spina and his associate, physicist Salvino D’Armati.
Salvino D’Armati and the First Eyeglasses
In fact, Salvino D’Armati (also spelled Salvino D’Armate and Salvino D’Armato, which means “son of Armato”, or Salvino degli Armati) alone is most often credited with the invention of the eyeglasses. Leopoldo del Migliore, in his 1684 history of Florence, claimed that a D’Armati memorial at the church of Santa Maria Maggiore featured the following claim: “Here lies Salvino degli Armati, son of Armato of Florence, inventor of the eyeglasses. May God forgive his sins. AD 1317.”
Some historians are suspicious of his claims as this tomb no longer exists. However, it is compatible with the accepted dates of Savlino D’Armati’s life, who was born in 1258 and died in 1312.
Armati had injured his own eyes while conducting light refraction examinations. Through these experiments he learned how to increase the appearance of subjects by viewing them through two pieces of convex glass. Armati’s glasses was prescribed for far-sightedness (hyperopia) and wore them himself following his injury.
Later during the early 14th century, concave lenses were discovered to improve near-sightedness (myopia). One of the earliest depictions of such lenses was featured in a 1517 painting by Raphael. In it, Pope Leo X wore glasses with concave lenses. By this time, eyeglasses had evolved from polished quartz to specially shaped and polished glass. This glass making technique encouraged greater production and more widespread use.
Benjamin Franklin Bifocals
Bifocals — lenses featuring both concave and convex lenses for correcting both types of vision problems — are believed to have been developed around 1760 by Benjamin Franklin (though some place the exact year to be 1874). These original bifocal reading glasses used a top lens for distant viewing and a lower lens for reading. In this era, they were referred to as bi focal reading glasses or bi-focal reading glasses. Today we frequently see them referred to as Benjamin Franklin Bifocals.
Benjamin Franklin, born on January 17, 1706, was a great American inventor and intellectual credited with many influential and groundbreaking discoveries and inventions.
Legend has it Ben Franklin bifocals came to be as a result of his growing tired of having to alternate between two different sets of eyeglasses. So he grafted two different prescriptions (two different lenses) into a single frame. This empowered him to see both far and near distances by simply looking down through the one lens or up through the other. This is why these glasses will be forever referred to as Benjamin Franklin bifocals or Benjamin Franklin glasses.
The discrepancy between claimed dates of invention (1760 and 1784) seems to simply be when he worked it out in a rough manner for himself and then when he refined the process and went public with it. To further confuse matters, the bifocal reading glasses as invented by Benjamin Franklin were only formally announced on May 23rd, 1785.
John Isaac Hawkins — who invented the trifocals — provided the actual title of “bifocals” in 1824 and credited Dr. Benjamin Franklin for their invention.
Ben Franklin’s bifocals featured convex lenses for close vision in the bottom half and concave lenses for far vision in the upper half. Bifocals were similarly constructed until the early 20th century.
Contemporary Bifocal Reading Glasses
Towards the end of 19th century Louis de Wecker devised a method to fuse the lenses together. This method was later patented by Dr. John L. Borsch, Jr. in 1908. Just a couple years later, the first single piece bifocal lens appeared. Bifocal lenses evolved rapidly throughout the 20th century. In the 1980s the first bifocal contact lenses appeared. We are now lucky enough to have a wide selection of choices from no line bifocals to bifocal sunglasses and even no line bifocal sunglasses.
I hope you enjoyed this history of glasses and that you now better understand the rich bifocals history behind each pair of Bifocal Reading Glasses._____________________________________