The blue lens is found to be Edward Carnby in Alone in the Dark: The New Nightmare.

The New NightmareEdit

Blue lens

It is a set of blue lenses with metal support useful to highlight the blood when illuminated by means of two clips you can attach them to the torch. Carnby finds them at the seaplane wreckage in heath Shadow Island, together with Wire Cutters , combining them with the flashlight beam of light makes it possible to highlight the traces of blood, thus identifying the three esoteric symbols useful to solve the riddle of the Chapel.