Here’s a useful book that, besides teaching you science, promises to be a potent creationism-killer: it’s Evolution’s Witness: How Eyes Evolved, by Ivan R. Schwab. Sadly, it’s $50, even with the $25 discount on Amazon, but you can look inside for free, and maybe ask your library to order it. It’s published by Oxford University Press, which has a record for high-quality books like this.
Remember that eyes have evolved anywhere between 40 and 60 times in animals, though the physical structure can reflect a homology of “initiating” genes: PAX6, for instance, is a key gene in initiating eye formation in both mice (and presumably other mammals) as well as fruit flies, even though insect eyes and vertebrate eyes, as structures, evolved independently.
Over at Science 2.0, Hank Campbell interviews Ivan Schwab, the book’s author. Schwab is an M.D.: an ophthamologist at the University of California at Davis who is afflicted with the curiosity of a naturalist. He speculates about when the first eye evolved, and has a unique answer to the perennial and misguided creationist question, “Of what use is half an eye?”