We lab of our custom prescription lenses on premises for complete control. Our Master, safety certified Optician has over 35 years of experience and will expertly craft each pair of glasses that leaves our facility. There are 2 basic types of prescription safety glasses. Conventional frames built specifically to withstand an impact, that are fitted with shatterproof polycarbonate lenses. Both frame and lens meet or exceed ANSI standards. The 2nd type is a sport optical system that has an optical adapter fitted behind them main lens. In many cases these adapters are easily removable so the glasses can be worn with or without the adapter in place. Further more they often feature interchangable main lenses for both night/day, and indoor/outdoor flexibility. Some even offer removable foam padding to further seal outwind and debris. Frame and lens will meet or exceed ANSI safety standards.