I've written before about the evolution of the eye (here & here for example. Now there's a whole issue of the most excellent science education journal Evolution: education & outreach devoted to this very topic - & it's free on-line right here! So if you're interested in following up on some of the latest work on this topic, do follow the link & download what interests you. I've got several articles to read & think about at my leisure (bwahahaha - leisure!) & might write about one or two here.