The present invention relates to an electrowetting element for a display device, a display device and a control system for controlling at least one electrowetting element. The electrowetting element comprises: a radiation valve comprising a first fluid and a second fluid immiscible with the first fluid, wherein the first and second fluids are configurable to change a characteristic of radiation passing through at least one of the first and second fluids; and an electrically switchable part switchable between a reflective mode for reflecting radiation incident on the switchable part and towards the radiation valve, and a transmissive mode for transmitting radiation incident on the switchable part through the switchable part and towards the radiation valve.