THE RESOLUTION OF INSECT COMPOUND EYES

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