A ceiling-recessed troffer luminaire for offices. Unique, multi-part optics with two thermoformed, edge-illuminated side diffusers. A three-layer construction consisting of a reflecting layer, a fiber optic layer and a non-yellowing opalized PMMA diffuser. An additional central module with WHITEPOINT optics consisting of opal lenses with 80° light distribution and a matte white, glare-reducing reflector. Designed to provide the highest working comfort. A central module that is CLICK-mounted in a white powder-coated extruded aluminum profile. White painted steel sheet housing. The electrical connector on the top of the fixture shortens the assembly time. Tool-free power supply connection and luminaire mounting in modular ceilings. The luminaire is equipped with a light source and separate lighting control equipment that cannot be replaced by the user.