Optical systems are described that include a switchable diffuser, a display panel, a lighting component and a diffuser controller. The diffuser controller is configured to switch the state of the switchable diffuser when the diffuser controller determines that the diffuser state is to be changed. The diffuser controller may be configured to vary an output level of the display panel in association with a change in state of the switchable diffuser. The optical system may also include a switching device which may be separable from the display panel.