Glasses, also known as glasses or glasses, are devices consisting of glass or hard plastic lenses mounted in a frame, which are usually held in front of the human eye through the bridge of the nose and the arm above the ear. Glasses are usually used for vision correction, such as presbyopic glasses and glasses for myopia. Safety glasses protect construction workers or laboratory technicians from flying debris; they may protect the sides of the eyes and lenses. Some types of safety glasses are used to prevent visible and near visible light or radiation. In some sports, such as squash, glasses are worn to protect the eyes. The wearer can use a belt to prevent the glasses from falling during movement or movement. The wearer of glasses for only part of the time may connect the glasses to the rope around the neck to prevent loss of glasses.

Sunglasses provide better vision in bright sunlight and protect the eyes from high-intensity ultraviolet light. Typical Sunglasses turn black to prevent glare or glare. Some special glasses are transparent in dark or indoor conditions, but will become sunglasses in strong light. Most Sunglasses don't have corrective power in the lenses; however, you can order Sunglasses with special prescription. Special glasses can be used to view specific visual information (for example, stereoscopic glasses) or 3D glasses can be used to view 3D movies. Sometimes, for aesthetic or fashion purposes, wear glasses without correction ability. Even with spectacles used to correct vision, plastic, wire and other materials can be used to provide a variety of designs for fashion purposes.

Since the 1970s, the number of short-sighted Americans has doubled, with almost three quarters of them wearing glasses. People need to wear glasses more and more, 93% of them are between 65-75 years old.