A dielectric collimator (1) comprising a center lens (3), the center lens comprising a light input surface (31) and a light exit surface (32), the light exit surface (32) being convex and substantially hemispherical, and the light input surface (31) comprising a central surface section (312) forming a light transmitting portion of the center lens adapted for receiving incoming light (5) and transmitting it to be emitted from the light exit surface, and a peripherally extending, annular outer surface section (311) being substantially plane and adapted for redirecting incoming light (5) in such a manner that the redirected light (7) undergoes TIR at the light exit surface and is emitted back out of the light input surface.