These safety glasses provide protection against moderate impact hazards and 99.9% of UV rays. The glasses are specially designed to provide the most protection with its wrap around lens design. They fit comfortably across and have adjustable arms to ensure the best fit. The tinted lenses also provide sun glare protection and the lenses are specially marked with the shade number. The yellow tint increases your visibility in dimly lit or foggy areas. These safety glasses comply with ANSI Z87.1 standards. The lenses are made from strong polycarbonate, which is far superior in impact resistance than glass. These glasses provide limited impact protection and are not unbreakable. We recommend you replace your safety glasses if they become scratched or pitted, because the impact resistance is severely reduced.