The frame can accommodate optical lenses up to +/-4 dioptres into the glass insert, fitted by an optician. The Optical Insert complete with optical lenses can then be easily clipped to the bridge of the Protos Integral Safety Glasses, leaving them fully protected behind the glass of the Safety Glasses.

A major advantage of the integrated glasses insert is that there is no pressure at the temples, under where the ear defenders are positioned, which can be caused by the legs of normal glasses, resulting in uncomfortable pressure on the head.