The Trifecta by Jack Armour, have a large lens with a slight curve in the frame front. They have a removable and replaceable foam gasket to make these positively sealed safety glasses. These safety glasses prescription are suitable for single vision, bifocal and progressive lenses. They meet Australian and International standards 1337.6 medium impact. They also have an adjustable strap that can be added to the frame.
The ASW Trifecta safety frame is suitable for leaded x-ray glass lenses. They are available in no prescription, single vision, bifocal or progressive/multifocal prescription lenses.