Smartlens Safety Glasses, Photochromatic Lens, Clear Frame

Features photochromic lenses that lighten and darken as outdoor lighting conditions change. Designed for comfort, the glasses come with spring adjusted temples that provide a customized fit on either narrow or wide faces, a soft nose bridge that adjusts, and a nylon brow thats easy going on the forehead. The impact-resistant polycarbonate lenses absorb 99.9% UVA and B rays. Recommended for use during chipping, chiseling, drilling, grinding, machining, masonry, pouring/casting, power fastening, riveting, sanding and sawing. Transition from light to dark takes less than 20 seconds (allowing just 22% light transmission), and dark to light takes less than 3 minutes (allowing 77.5% light transmission). Air temperature may affect the lens transition time.