Glasses, also known as eyeglasses (formal) or spectacles, are frames bearing lenses worn in front of the eyes. They are normally used for vision correction or eye protection. 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. Other types of glasses may be used for viewing visual information (such as stereoscopy) or simply just for aesthetic or fashion purposes.

Modern glasses are typically supported by pads on the bridge of the nose and by temple arms (sides) placed over the ears. CR-39 lenses are the most common plastic lenses due to their low weight, high scratch resistance, low dispersion, and low transparency to ultraviolet and infrared radiation.[citation needed] Polycarbonate and Trivex lenses are the lightest and most shatter-resistant, making them the best for impact protection.

Safety glasses are usually made with shatter-resistant plastic lenses to protect the eye from flying debris. Although safety lenses may be constructed from a variety of materials of various impact resistance, certain standards suggest that they maintain a minimum 1 millimeter thickness at the thinnest point, regardless of material. Safety glasses can vary in the level of protection they provide. For example, those used in medicine may be expected to protect against blood splatter while safety glasses in a factory might have stronger lenses and a stronger frame with additional shields at the temples to protect from sawdust, flying wood, or metal. The lenses of safety glasses can also be shaped for correction.

As the glasses are not big goods, so labels of glasses also very small, just like a little piece of hangtag or sticker, but many sales start to use seal tags on it too. The seal tags lets glasses are seems has more scale. Logo on seal tags can enhance product value more than a paper tag.