The invention relates to a light guiding optical system comprising at least two light guides (6, 7, 8), to which is assigned a light unit (9) with at least one source (91) of light. The inner light guide (6) is provided with an input surface (61) with which it is situated opposite the light unit (9) and is further is provided with a broken stepped transition surface (67), which comprises at least one decoupling surface (64) and at least one reflective surface (65), whereby the broken stepped transition surface (67) of the inner light guide (6) is associated with an input surface (77, 87) of a coupling light guide (7, 8) which comprises at least one coupling surface (71, 81).