Definition: Museum für Naturkunde Berlin (Zoological Collections) (ZMB). Berlin, Germany. URL for main institutional website: http://www.naturkundemuseum-berlin.de Formerly Zoologisches Museum der Humboldt-Universität zu Berlin
Definition: superposition compound eyes where each ommatidium is equipped with a lens cylinder arrangement, producing the equivalent of a pair of lenses, with the first lens producing a small image halfway down the structure and the second lens turning the image back into a parallel beam. In the process the ray direction is reversed. Thus, the emerging beam is on the same side of the axis as the entering beam—the condition for obtaining a superposition image from the whole array.