The Evolution And Styles Of Eyeglasses

By Author: Sallie West
Total Articles: 3
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As an "old technology," eyeglasses have maintained their popularity even after the development of contact lenses and laser eye surgery. Most people call them simply "glasses." Eyeglasses correct vision by situating a glass or plastic disc called a lens before each of the wearer's eyes. A frame with temple arms that hook over or rest on each ear, and pads on the nose, helps to keep the lenses in place. The first known reference to magnification appears in Egyptian hieroglyphs from the 5th century BCE. Seneca the Younger, born a few years before Jesus, was the first to write about artificial magnification. But eyeglasses as we recognize them did not turn up until the 13th or 14th century, in Italy. As many of us learned in school, bifocals were invented by a scientist named Benjamin Franklin, who needed a tool to correct his nearsightedness.Since Franklin thought of them, reading glasses have evolved into many types. Franklin's lenses perched low on the nose in half-glasses, and some people still wear those today. Bifocals with a clearly-divided split lens enabled our grandparents to see distant objects via the upper half and ...
... read through the lower. Opticians today grind lenses that adjust smoothly from distant to close as the eye looks downward. Some eyeglasses even have multiple focal lengths in a single lens.Millions of plain, non-prescription reading glasses sell off the shelves of pharmacies and department store chains in the United States. Customers seeking to sharpen their vision bought roughly 30 million units of reading glasses each year in the 1990s.Eyeglasses have some disadvantages. They are subject to damage and smearing. Glass and plastic lenses will scratch or shatter, necessitating repair or replacement. They can also become smudged with food grease, dirt, body oils, and pollution. Raindrops or sudden changes in the surrounding temperature also fog or cloud eyeglasses and decrease visibility.Sunglasses continue to be a popular form of eyeglass wear. Darkened lenses protect the wearer's eyes from bright sunshine and fluorescent lights, and ultraviolet radiation if designed for that. Gray or gray-green shading is the best for keeping colors natural. Elderly persons or people with impaired sight like yellow-tone sunglasses because they heighten color contrast and render better depth perception. Brown lenses are favored by golfers, but they do not preserve natural colors as accurately. Sunglasses also come in blue, purple, dark green, and other tones for appearance.Safety glasses are usually larger and fit tightly against the skin around the eyes in order to protect them from flying sawdust, blood, sparks, and metal chips, depending on one's work. Usually made of polycarbonates, which are a form of lightweight and shatter-resistant plastic, they often can fit over the wearer's own corrective eyeglasses.Once regarded as unfashionable, eyeglasses became "cool" in the mid twentieth century when early pop and rock idols like Buddy Holly and John Lennon were regularly photographed wearing them. Luxury brand eyeglasses and shades such as Vuarnet, Aviator, and Ray Ban were joined by familiar names in clothing design, like Armani, Prada, and Gucci. More recently, manufacturers have cut deals with celebrities (or their heirs) to put their names on eyeglass lines, including Sophia Loren, Ernest Hemingway, and even Sponge Bob Squarepants.Click here for a good informational starting point.