A monitoring device for safeguarding a driven element against undesired collisions with an object lying on the movement path of the driven element including at least one transmitting element and a multiplicity of receiving elements, wherein the at least one transmitting element is arranged in a horizontal boundary region of an opening to be monitored, where the opening can be at least partially closed by the driven element, and the multiplicity of receiving elements are arranged in a horizontal, opposite boundary region in a distributed fashion along the opening to be monitored, wherein the at least one transmitting element, together with each of the multiplicity of receiving elements forms a light barrier arrangement, which can be evaluated individually.