Abstract: Systems for indicating visibility of a blind spot to a driver are provided. In some embodiments, the systems comprise: a housing; a mirror coupled to the housing, wherein the mirror is adjustable in at least a horizontal direction with respect to the housing; and a directional light source rigidly coupled to the housing such that a direction of the light source is substantially parallel to at least a portion of a typical driver's blind spot during operation of a vehicle to which the side mirror assembly is coupled, wherein the direction of the light source is angled with respect to the housing such that light emitted by the light source is reflected by the mirror into a passenger compartment of the vehicle to which the side mirror assembly is coupled in at least two positions of the mirror separated by at least ten degrees of horizontal rotation of the mirror.