Part of the charm ... or that there are five distinct types of compound eyes. Aside from specialist reviews, this is the best text-book treatment of eye evolution that I know of.

BBC Bitesize talks you through the names you probably never knew for five parts of the body you see all ... something from of the corner of your eye. A shorter - but not necessarily snappier ...

Alternatively, students could explore the different parts of the eye. Given a diagram of the eye, students could be asked to add labels and annotation to describe the different parts.