Abstract
Like the majority of other insects, the blowfly has five eyes: three ocelli on top of the head and two compound eyes at the side. The ocelli retinae compose a few hundred photoreceptors whose light-sensitive structures lie inside the focal distance of the lens. Ocelli are believed to act as wide field brightness sensors and are not suited to perceive fine spatial details. Degradation of visual perception by blurring during self-motion is principally the same in all types of eyes. The transfer of high spatial frequencies can be optimized by minimization of the retinal slip, using the necessary compensatory eye movements.