Abstract: A system is provided for detecting obscurants on an outer surface of a lens of a vehicle lamp of a vehicle. The system includes a support, as well as an infrared (IR) light emitter-detector module coupled to the support. The IR light emitter-detector module includes an IR light emitter configured to emit IR light towards an inner surface of the lens, as well as an IR light detector configured to measure an intensity of IR light reflected by the obscurants. A controller is also coupled to the IR light emitter-detector module. The controller is configured to control the IR light emitter-detector module, determine a level of light obstruction based on the measured intensity of reflected IR light, and when the level of light obstruction meets predefined criteria, issue a warning.