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. It is of course impossible for humans to perceive what an insect sees. In most cases the compound eyes will see only form and movements, but the dragonfly , who has to catch his prey in flight, undoubtedly must have a detailed view of his near surroundings.
Insect eyes can change considerably between the larval and the adult stage.
When you look into the details of the compound insect eye, there are many differences when you compare them with our eyes. But amazingly there is a very close resemblance between the genes that control the development of eyes in a house fly and in man, making it a little bit easier to understand the many times that eyes developed independently in different classes of animals. Other sets of control genes cause the differences between animal groups. We find compound eyes even in trilobites, crustaceans already present 500 million years ago. The lens parts of their eyes are often marvellously preserved, due to the fact that the material of these eyes consists of calcite crystals.