Why do insects have compound eyes?
Compared with single-aperture eyes, compound eyes of insects have poor image resolution; however, they possess a very large view angle and the ability to detect fast movement and, in some cases, the polarization of light.Although insects' eyesight image is very poor,they can sense when there is reydators by using their five senses,just like humans,they are the sense of hearing,seeing,touching,tasting and smelling.
Antennae and compound eyes are appendages that insects have and that arachnids lack. Specifically, insects have three (3) pairs of legs and one (1) pair of antennae. In contrast, spiders have four (4) sets of legs and no antennae. They also see through a series of singular, lensed eyes whereas insects have compound eyes.
Insects can have a number of eyes and moreover, eyes of different types; single eyes and compound ones. In contrast with our eyes, insect eyes are immovable and unable to focus. Insects are short sighted. Butterflies are probably the most far sighted, they can see perhaps a few meters, while bumblebees only have a range of a half meter. But many insects are helped a lot by their sometimes unbelievable sensitivity for scents.