The best safety glass lenses are made of a polycarbonate plastic and should be 2-3 millimeters thick. The frames should be sturdy and, when using power tools or chemicals, should have a wrap around protection to act as a shield. Safety glasses should be used when doing home repairs, carpentry, when working with chemicals, or when working with power lawn tools such as edgers or weedeaters. Any racquet sport would benefit from safety glasses, even tennis. Consider using them while playing basketball or when cycling as these are two additional sports where eye injury may occur.
Ultraviolet radiation comes from sunlight, which contains three forms of radiation.
Ultraviolet C is the most powerful of the three but is fortunately blocked out by the earth's atmosphere. As more and more of the ozone layer is being depleted, the more of the ultraviolet B radiation reaches the surface of the earth and you. Ultraviolet B contains enough to disrupt human DNA, the very stuff that makes our cells work. The good news is that ultraviolet B cannot penetrate our skin too deeply into the body. The bad news is that it does penetrate enough to effect your eyes and the skin itself.