Eye Glasses

Glasses, spectacles, or eyeglasses are frames-bearing lenses worn in front of the eyes normally for vision correction or eye protection or for protection from UV rays. Special glasses are used for viewing three-dimensional images from two-dimensional displays or experiencing virtual reality.

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.Glasses frames are commonly made from metal, horn or plastic. Lenses were originally made from glass, but many are now made from various types of plastic. These materials reduce the danger of breakage and weigh less than glass lenses. Some plastics 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 vision abnormalities such as myopia, allowing thinner lenses for a given prescription.