Prescription safety lenses are available in Polycarbonate, CR-39 Plastic, and Glass materials. When manufactured to the lab guidelines established by ANSI Z87.2, all three materials are approved for use in safety prescription eyewear. 

Whenever possible, we recommend the use of Polycarbonate lenses for safety eyewear, as it is the most impact resistant lens material available today and offers significantly greater protection and safety for your eyes.