The present invention relates to a light fitting or light fixture (1) that includes a light source (2), a reflector (3) and a glass cover (4), wherein the light source (2) has a generally punctiform configuration and wherein the surface of the glass cover (4) includes a large quantity of lenses (5) which are intended to diffract the light asymmetrically so as to illuminate a rectangular square surface area at right angles to the optical axis of respective lenses (5). The invention is characterized in that the glass cover (4) comprises mutually parallel and upwardly projecting crests (7) defined by two mutually opposing side surfaces (8, 9) that are angled with respect to each other, wherein each crest (7) has a wave form in the longitudinal direction of the crest such that the height of the crest (7) will vary, in that the bottom surface between two mutually adjacent crests has a corresponding wave form such that the height of the bottom will vary, in that the width of the crest (7) at its bases (10) is constant or varying, meaning that the side surfaces (8, 9) of the crests (7) will have a wave form that corresponds to the variations in height of the crest, wherein each wave section of a crest (7) forms a prism for diffracting incident light from the reflector (3), whereby the top angle of the crests (7) causes light to be spread in a first direction and where the wave form of the crest side surfaces (8, 9) causes light to spread in a second direction at right angles to said first direction and in that the light from each prism illuminates a part of the illuminated surface.