Eyeglasses Shoppin Guide

What Are Prescription Eyeglasses Made Of?

Prescription eyeglasses and prescription sunglasses are manufactured in a variety of materials. The most basic is the glass lens. The glass lens is by far the best in absorbing ultraviolet light. It comes in several different colors and is, of course, scratch resistant. It is also one of the least expensive. The downfall to the glass lens is the weight of a pair of prescription eyeglasses made of glass. They are also very breakable and have to undergo a heat-treated process to ensure durability.

Another material used to manufacture prescription eyeglasses including bifocal eyeglasses , rimless glasses are the High-Index plastic lens. It also absorbs ultra violet light well. This type of lens is much lighter in weight than the glass lens; however, they are also very expensive and can be scratched very easily.

Resin Plastic is another type of material used in manufacturing the prescription eyeglass lens. They are the lightest of all lenses, but do not offer the high level of protection against ultra violet light like classic eyeglasses that the other lenses offer.

Some prescription eyeglasses are tinted with a wide variety of colors and shades. The purpose of the tint is to reduce the glare from certain situations: such as bright lights, computers television sets, etc. Another reason for the tinting of the lenses are to offer comfort to the eyes. Also, people order tints on their rimless eyewear and eyeglasses for the fashion.

Glass and most plastic lenses are coated with a UV protection coating. Ultra violet rays can cause severe damage to the eyes. It is very important to protect your eyes while out in the sun.

Another coating that is added to a pair of prescription eyeglasses is the scratch-resistant coating. Sometimes this coating is applied at the manufacturer and other times it can be added right there at the eye doctors office. It must be said, however, that even while this coating can aid in the durability of the lens, it does not make the lens scratch proof.

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Introduce Of Glasses

Glasses, also called eyeglasses, optical eyewear or spectacles, are frames bearing prescription lenses worn in front of the eyes, normally for vision correction, eye protection, or for protection from UV rays.

Modern glasses are typically supported by pads on the bridge of the nose and by temples placed over the ears. Historical types include the pince-nez, monocle, and lorgnette.

Eyeglass frames are commonly made from metal or plastic such as metal glasses. Lenses were originally made from glass, but many are now made from various types of plastic, including CR-39 and polycarbonate. These materials reduce the danger of breakage and weigh less than glass lenses. Some plastic glasses also have more advantageous optical properties than glass, such as better transmission of visible light and greater absorption of ultraviolet light. Some plastics have a greater index of refraction than most types of glass; this is useful in the making of corrective lenses shaped to correct various vision abnormalities such as myopia, allowing thinner lenses for a given prescription.

French Empire gilt scissors glasses c.1805Scratch-resistant coatings can be applied to most plastic lenses giving them similar scratch resistance to glass. Hydrophobic coatings designed to ease cleaning are also available, as are anti-reflective coatings intended to improve night vision and make the wearer's eyes more visible

CR-39 lenses are the most common plastic lenses due to their low weight, high scratch resistance, and low transparency for ultra violet and infrared radiation. Polycarbonate lenses are the lightest and most shatter-resistant, making them the best for impact protection,yet offer poor optics due to high dispersion, and having a low Abbe number of 31.

Not all glasses are designed solely for vision correction but are worn for protection, viewing visual information (such as stereoscopy) or simply just for aesthetic or fashion values. Safety glasses are a kind of eye protection against flying debris or against visible and near visible light or radiation. Sunglasses allow better vision in bright daylight, and may protect against damage from high levels of ultraviolet light.

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