Vent Holes On The Brow Guard Help Keep The User Comfortable As Does The Adjustable Temple Length. The Anti Fog Lens Helps Ensure That The Wearer Will Have An Unobstructed View When Working In Applications Such As Power Tool Work Sawing/Drilling In Metal Or Wood, Hammering Or Overhead Work. Meets The High Impact Requirements Of The American National Standards Institute's ANSI Z87.1-2010 Standard.