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 ofultraviolet light. Other types of glasses may be used for viewing visual information (such as stereoscopy) or simply just for aesthetic or fashion purposes.

An unpopular aspect of glasses is their inconvenience. Though modern frames can be both lightweight and flexible, and new lens materials and optical coatings are resistant to breakage or scratching, glasses can still cause problems during rigorous sports.

Speaking of glasses packaging, I found that many glasses are hangingplastic seals. I always can see sticker posted on glasses, it looks cheaper and perhaps peel off will be left traces on glasses, plastic seals are have more grades. Not only good function, but also good packaging, put brand on plastic seals make a good image than just piece of paper.

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.