The resolution of insect compound eyes

The spatial resolution of compound eyes is determined by their interommatidial angles, by the optical quality and rhabdom dimensions of the ommatidia, and by illumination level. Among insects, interommatidial angles vary from tens of degrees in Apterygota, to as little as 0.24 degrees in dragonflies. Resolution better than this is not attainable in compound eyes of realistic size, because of the limit imposed by diffraction. The smaller the interommatidial angle, the greater the distance at which objects-prey, predators, foliage, or flowers-can be resolved. insects with different lifestyles have contrasting patterns of interommatidial angle distribution, related to forward flight, capture on the wing, and predation on horizontal surfaces.