There are two basic types of eyewear design in the United States street wear and safety wear. Street wear glasses are never appropriate as safety eye protection. Their design emphasis light weight and fashion. In safety glasses the frame is made to withstand high impact loads from objects striking the front of the lens. The lens is designed to decrease the chance that a safety lens will pop through the frame cutting the wearers face.
Lenses also have different impact resistance. One of the most shatter resistant lenses is a lens made of polycarbonate. For this reason polycarbonate lenses are highly recommended for children. This type of lens resists shattering and lowers the risk of shattered glass in the eye.
To be a true pair of safety glasses that are OSHA approved for use in the work place the lens and frame should be marked with the ANSI Z87 mark. This type of eyewear is often modified with side shields or special tints for use in specific environments.
