Blind spot detector

A warning device for mounting onto a vehicle, in order to attract the attention of the driver when another vehicle (2) or object is located in a position that is wholly or partially critical for the driver. The device comprises two sources (5, 6) of laser radiation arranged at a distance from each other, a convex lens (8) arranged outside of each source and a position-sensitive radiation detector (7) arranged between the sources (5, 6). The device reacts with different levels of warning signals on the detection of direction indicator (58), angular deviation (60) of a wheel or the steering wheel, speed (62), etc., in combination.