UV engravers and markers (e.g. at a wavelength of 355 nm) are used for so-called cold marking of sensitive plastics, glass or medical instruments, very often in semi-enclosed workplaces. Operators are constantly at risk from scattered invisible radiation, the short pulses of which cause acute inflammation of the cornea and conjunctiva. The ideal balance between complete blocking of the hazardous UV spectrum and a perfectly clear view allows for detailed monitoring of the material being engraved.