Wear the adjustable Thermo Scientificâ„¢ Nalgeneâ„¢ Polycarbonate Face shield over safety glasses. With an optically clear window made of 1/16″ (1.5mm) thick polycarbonate, this face shield provides impact protection as well as protection from UV light in the 200-360nm range. It is useful in germicidal procedures as well as reading of chromatographic/electrophoretic strips and gels.