ProVisGuard protective spectacles offer limited protection against moderate impact hazards, metal chips, particles, and sparks. These lenses are not unbreakable or impenetrable. This polycarbonate product offers impact resistance than glass lenses. ProVisGuard protective spectacles meet the performance standards of ANSI Z87.1-2003. Please refer to your ANSI manual for safety specialist for proper selection as some applications may require face-shields, machine guards, etc.