The Ossa OTG is an ANSI Z87 -approved over-glasses safety glass. These durable and affordable over-the-glass (OTG) safety glasses accommodate prescription frames up to 135mm wide and block 99.9% of UVA, UVB and UVC rays. Impact-resistant polycarbonate lenses and durable nylon frames mean the Ossa will stand the test of time and offer peace of mind in hazardous conditions. Plus, the Ossa comes available with both clear and smoke-colored lenses. For those who require prescription glasses, the Ossa is the ultimate solution to keep eyes protected.