Actuating apparatus , having a rotatably mounted actuating element that is capable of being transferred into different rotational positions, for operating a closure apparatus for the opening in a wall, wherein the actuating apparatus has a light source emitting a light beam , a detector , which is configured and arranged for receiving light of the light beam and for generating an electrical signal, and wherein the actuating apparatus has a light beam influencing means , which is connected for conjoint rotation with the actuating element and changes at least one property of the light of the light beam that is detectable by means of the detector in dependence on the rotational position of the actuating element , characterized in that a. the time period from the beginning of a transfer operation from one rotational position of the actuating element into another rotational position up to an onset of a change in the detectable property of the light beam differs for different movement directions of the actuating element , or, in the first or the second rotational position, the light beam passes eccentrically through a light-transmissive transmission region of the light beam influencing means , or, in the first or the second rotational position, the light beam passes through an asymmetrically formed light-transmissive transmission region of the light beam influencing means , and/or in that , b. in the first rotational position, the light beam influencing means reflects the light beam towards the detector , and, in the second rotational position, allows it to pass through a transmission region such that the light beam does not arrive at the detector , and/or in that c. a further light source emitting a further light beam and a further detector , which is configured and arranged for receiving light of the further light beam and for generating a further electrical signal, are present, wherein the light beam influencing means also acts on the further light beam in dependence on the rotational position of the actuating element . a. the time period from the beginning of a transfer operation from one rotational position of the actuating element into another rotational position up to an onset of a change in the detectable property of the light beam differs for different movement directions of the actuating element , or, in the first or the second rotational position, the light beam passes eccentrically through a light-transmissive transmission region of the light beam influencing means , or, in the first or the second rotational position, the light beam passes through an asymmetrically formed light-transmissive transmission region of the light beam influencing means , and/or in that , b. in the first rotational position, the light beam influencing means reflects the light beam towards the detector , and, in the second rotational position, allows it to pass through a transmission region such that the light beam does not arrive at the detector , and/or in that c. a further light source emitting a further light beam and a further detector , which is configured and arranged for receiving light of the further light beam and for generating a further electrical signal, are present, wherein the light beam influencing means also acts on the further light beam in dependence on the rotational position of the actuating element . <EOS>