Focused on Facts
The first eyeglasses are generally thought to have been created in 1285 and were made of quartz, since glass at that time was too flawed to be good for glasses.
Eyeglasses work by taking on some of the light ray management that the eye would do in a person with perfect vision. If you’re nearsighted, your glasses focus incoming light rays onto the retina of your eye so that faraway objects you see aren’t blurry. If you’re farsighted, eyeglasses spread the light over a wider area of the eye’s retina, bringing nearby objects into focus.
Sunglasses in the form of slits cut into walrus ivory have been used to reduce snow glare by Inuit people for 2,000 years.
The idea may seem obvious now, but eyeglasses went about 450 years before the development of frames with hooks that go behind the ears.
In addition to accomplishments in science, writing, politics, diplomacy, and more, Benjamin Franklin was also the inventor of bifocals, which allow wearers to focus on objects both near and far.
Most modern “glasses” lenses are plastic, which tend not to shatter and are hence safer for the wearer.
About 75% of adults need some form of vision correction.