Pseudopupils of Compound Eyes

Abstract

“I come to the discussion of a remarkable optical phenomenon the unravelling of which has caused me a good deal of worry.” In this way Sigmund Exner (1891, p. 162) begins the chapter on pseudopupils in his invaluable monograph “Die Physiologie der facettirten Augen von Krebsen und Insecten”. His worry has proved worthwhile because his recognition that pseudopupils are optical revelations of the interior of compound eyes has been of longlasting and immense importance. The aims of this chapter are to show that pseudopupil phenomena provide a direct and deep insight, both figuratively and literally, into compound-eye structure and function, and also to indicate possible paths for future research.