A vehicle rearview mirror system includes a rearview mirror assembly comprising an electro-optic reflective element and, preferably, at least a first and a second photo-sensor, both facing generally in a common direction. The system further includes a light piping element that pipes light to the first photo-sensor from a light environment different from the light environment to which the second photo-sensor is exposed. The first photo-sensor comprises a semiconductor photo-sensor sensitive both to visible light and to infrared radiation. A spectral filter is disposed in front of the first photo-sensor to reduce the amount of infrared radiation incident thereat. The spectral filter preferably comprises at least one of a) a filter element having at least about 60% visible light transmission and having less than about 10% transmission in the near-infrared spectral region; and b) an infrared attenuating dye in a polymer material.