Flat light guide for a vehicle lighting device and a vehicle lighting device

A flat light guide for a vehicle lighting device, which comprises a rear end and a front end arranged opposite the rear end, the front end being provided with a light output surface, wherein the flat light guide is defined by a pair of side surfaces between the rear end and the front end, wherein the light guide has a base plane (X-Y) and is provided at its rear end with at least one collimating element, which is arranged transversely or obliquely with respect to the base plane (X-Y) of the flat light guide, and opposite the collimating element is arranged an obliquely inclined reflective surface adapted to reflect light from the collimating element into the flat light guide, the collimating element being adapted for light entry from a light source into the flat light guide and the flat light guide being adapted to guide the light from the collimating element between the side surfaces of the flat light guide to the light output surface, wherein the flat light guide has an end tip (S) defined by the peripheral area (O) of the light output surface and the side surface, wherein at least one obliquely inclined reflective surface includes at least one compensating optical element which is adapted to intentionally reflect at least parts of the light incident on the obliquely inclined reflective surface into the direction of the rays (P2) intentionally obliquely to the side surface of the flat light guide as far as to a region of the end tip (S) and the side surface is adapted to reflect these intentionally obliquely directed rays (P2) also to the peripheral area (O) of the light output surface.