Abstract: A rotary control device is provided comprising a light source (22), at least one light receptor (24) radially spaced from the light source (22), a light director (14) having means for directing light from the light source (22) to the receptor (24) and means for rotating the director (14) so that the light director (14) is in a first position when not directing light from the light source (22) to the light receptor (24) and the light director (14) is in a second position when directing light from the light source (22) to the light receptor (24). In another aspect of the invention, the optical rotary device further comprises an isolator (26) made of opaque material which surrounds four sides of the light receptor (24) and four sides of the light source (22). In a further aspect of the invention the light director includes a reflector (46) for directing the light from the light source (22) to the light receptors (24).