Magnification of the past

Abigail O’Bright

Glasses… The amazing invention that many people, including myself, wear daily in order to appreciate the world around us. With all of the advancing technology around us, it’s hard to imagine a world where glasses didn’t exist. I bet you’ve never even questioned how these wonderful pieces of glass came to be. But, I’m going to tell you anyway!

Before we get into our typical corrective lenses, we have talk to about

sunglasses. Why, might you ask? Well, truth be told, sunglasses may have been invented before corrective lenses. Blocking the sun was most likely a more attainable feat than altering the focus of light rays. It might have even been a more recognizable and solvable issue since people weren’t aware of the total function of the eye or the fact that they weren’t seeing in focus. In Rome, Neto, an emperor, used emeralds to block the sun’s glare and Inuits used ivory to block the sun. They would flatten walrus ivory and cut tiny slits into them (figure 1). In present times, we know that this form of light reduction would act in accessory to the constriction of the pupils, but in prehistoric times, this would have been a breakthrough. When the 12th century came along, Chinese judges would wear a type of sunglasses made of quartz, not because of the sun, but to hide their expressions from the people sitting in court. One might say this has come full circle and people are using sunglasses for that purpose today!

Shortly before the 1300s, corrective lenses, or magnification for better words, were discovered by accident. Seneca noticed while doing work at his desk that the water in his fishbowl magnified the papers behind it. Wow! This idea of water and glass was transformed into a sort of reading sphere. These flat-bottomed spheres were filled with water and placed over reading material to enlarge the words or pictures behind it (figure 2). In Venice, a portable version of these spheres was carried around in day-to-day life. They were called “reading stones” and could be transported anywhere.

These reading stones later developed into a sort of spectacle, where 2 spheres

https://www.sophisticatededge.com/eyeglasses-a-brief-historical-account.html

were paired together and could sit over the bridge of the nose. You certainly couldn’t play soccer in them, but they would help see things from a distance. Near the 14th century, biconvex lenses were invented to enhance vision at a distance and glasses could be more fixed to the head by using a string or held close to the eyes by using a stick (figure 3).

Wearable glasses were then created in Italy, by blowing glass into a sphere and surrounding it with leather or wood to make a frame. These were most often worn by monks, but soon became more popular. Glasses were then limited to the rich, since they required a lot of talent to build (experienced glassblowers), and talent means it's pricey. These glass blowers would use information from an eye test to get the right angle of curvature and create a pair of glasses that were specific for each person. Obviously, the precision was not as precise as it is now, but we are getting there! This is most likely where glasses got their stereotype of representing intelligence and prosperity, since wealthy people were the only ones who were able to get an education and were able to afford glasses. These glasses were made with a concave lens (bulging inward in the center) to correct

In 1727, Edward Scarlett developed the current style of glasses where they hook around your ear to hold in place. His original style was a stick attached to a lens with a loop at the end (figure 4). These solved the problem of having to hold the glasses up to your face to use them and allowed them to be worn more conveniently. It wasn’t until later; we see glasses with a curved end to loop around the ear.

Benjamin Franklin followed suit and developed a pair of bifocal lenses, where each lens was split to see both far and close by with a single pair of glasses, and Sir George Biddle Airy invented a lens to correct an astigmatism. Glasses are currently being made in a variety of styles and can be suited to most any (most) eye correction. What started as a convenience in the sun, became a tool to block facial expressions, which later developed into something that clarified the world around us.

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References

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The Fascinating History of Eyeglasses | All About Eyes. https://allabouteyes.com/see-past-

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Who Invented Eyeglasses? - Who Was Glasses Inventor?

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