A device (1 26) for use in a medical treatment room includes at least one control unit (2, 6 18) designed as a light guide and at least one light source (3, 3′ 21) which emits light with a wavelength between 380 nanometers and 420 nanometers, particularly 405 nanometers, and is arranged in such a manner that emitted light is coupled into the light guide. The light guide is designed in such a manner that light exiting the light guide again at least partially illuminates the surface of the control unit (2, 6 18).
