An electronic device includes a protective layer above a proximity sensor having a radiation emitter and a radiation detector. A groove, which may be wedge shaped, is formed in the bottom surface of the protective layer. A radiation barrier, which may be reflective or absorptive material, is placed in the groove in the bottom surface of the protective layer. A light blocking coating may be applied to the bottom surface and the groove of the protective layer to prevent the passage of visible radiation and permit the passage of infrared radiation. A radiation shield may be positioned between the emitter and the detector directly below the radiation barrier. Alignment features may be formed on the mating surfaces of the radiation barrier and radiation shield to align the protective layer with respect to the radiation shield and proximity sensor.