An interior mirror system suitable for use in a vehicle comprises an interior rearview mirror assembly with an information display disposed within the housing and behind the reflective element and viewable through the reflective element by a driver of the equipped vehicle viewing the reflective element when the interior rearview mirror assembly is normally mounted to an interior portion of the equipped vehicle. A control is responsive to a photo sensor and operable to distinguish between daytime and nighttime lighting conditions. The control is operable to vary the intensity of the information displayed by the information display as viewed through the reflective element by the driver of the equipped vehicle. When the information display is operating during daytime lighting conditions, the control may adjust the intensity of the displayed information to at least about 1000 cd/m2 as viewed through the reflective element by the driver of the equipped vehicle.