A light guiding layer comprises an optical incoupling structure (3) on which light from a light source (7) is incident, said optical incoupling structure (3) having a slanted surface (15) configured to give the light a first directional distribution by reflecting the light in a first general direction, by total internal reflection within the layer, towards a reflecting structure (5). The reflecting structure (5) is configured to give the light a second directional distribution by reflecting the light in a second general direction towards the optical incoupling structure (3), and at least a part of the light reflected in the second general direction is transmitted through the slanted surface (15) of the optical incoupling structure (3). A display unit, a segmented backlight, a luminaire, and a method is also disclosed.