The invention relates to a system (100) for sensing ambient light intensity, comprising a wearable device (10) with at least one pair of light receivers (20, 22, 23, 24, 25) arranged in two different positions for receiving light from the two different directions, and a control unit (110) configured to determine a directional illuminance based on light intensities of the light received by the pair of light receivers (20, 22, 23, 24, 25).