in a non glare screen of superposed prisms 1 the ellipsoid lamp 5 is mounted in a fitting 10 which also supports in a conventional manner a fixing member 11 for the prismatic screen the ellipsoid lamp 5 of course can be also mounted horizontally in a rectangular prismatic screen as indicated in fig4 a and 4b the screen is again assembled of superposed prismatic frames forming together a screening column in the same manner is screened a fluorescent lamp 12 shown in fig5 a and 5b the configuration and construction of the non glare screen 1 is the same as for the ellipsoid lamp of fig4 a and 4b the same advantages are obtained with the screen assembly of fig6 used for a light radiator built in a ceilings in this embodiment a fitting 10 and ellipsoid lamp 5 are arranged in an opening of a ceiling plate 13 a top part of the lamp projects below the plate 13 and is surrounded by the screen of this invention assembled of annular prisms 1 the arrows indicate that no radiation takes place in the intermediate part of lateral walls of the screen most rays are radiated downwards arrow 7 and a lesser amount of rays is directed upwards arrow 8 to brighten ceiling plates 13 fig7 shows a pendulum light emitter suspended from a ceiling 13 a large area illumination member 5 is coaxially surrounded by a cylindrical screen assembled of superposed prismatic rings the screen can be made either of a stack of individual rings or as a single piece with integral prisms the one piece screen is also free of lateral radiation from the intermediate part of its.