Edridge Green Color Percetion Lantern

EDRIDGE-GREENCOLORPERCEPTION LANTERN: This lantern enables tests to be made under conditions very closely allied to those found in everyday practice, while the colours were chosen are those which rapidly and definitely disclose any defects in colour perception. It is used by in screening of all personnel where colour perception is of paramount importance. The lantern consists of five rotating discs-three discs contain seven coloured glasses and one clear aperture, one disc contains seven various sized apertures and obturator, and one contains seven modifying glasses. The discs are held before a reflector containing a mains voltage lamp giving a controlled brilliancy.