The Model 2075 is a comfortable and lightweight yet sturdy unifit nylon frame. All lenses are standard with .75 Pb Lead Equivalency, We offer High Light Transmission lenses that offer over 92% visible The lenses offer a 0.75 lead equivalency and are 2.6mm thick. It also has an extremely hard nature for being lead glass that gives it excellent scratch resistant properties. All lenses are heat treated and can pass the drop ball test for dress eyewear.utilizing state of the art robotic free-form lens surfacing technology which allows us to provide the highest quality glasses available on the market.