Techniques are described for backlighting electronic headset display panels. The backlight can include a light guide plate that is illuminated via a light transmitting element that is coupled to a light source. The light guide plate, in turn, illuminates the display panel. The light source is located within the headset but is disposed remotely from the display panels. A photodiode is coupled to a surface of the light transmitting element and is configured to detect a characteristic of the light transmitted by the light transmitting element.