@farmerman,
Dawkins is usually writing for a popular audience. If someone wanted to have a more detailed understanding of evolutionary mechanisms (like of vision). Here are a few more technical journal articles
Land, M.F. and Nilsson, D.-E., Animal Eyes, Oxford University Press, Oxford (2002).
Lee M.S.Y., Jago, J.B., Garcia-Bellido, D.C., Edgecombe, G.E., Gehling, J.G, Paterson, J.R. 2011. Modern optics in exceptionally preserved eyes of Early Cambrian arthropods from Australia. Nature 474: 631-634
Gehring WJ (2005). "New perspectives on eye development and the evolution of eyes and photoreceptors". J. Hered. 96 (3): 171–84. doi:10.1093/jhered/esi027. PMID 15653558
Parker, A. R. (2009). "On the origin of optics". Optics & Laser Technology 43 (2): 323–329. Bibcode:2011OptLT..43..323P. doi:10.1016/j.optlastec.2008.12.020.
Parker, Andrew (2003). In the Blink of an Eye: How Vision Sparked the Big Bang of Evolution. Cambridge, MA: Perseus Pub. ISBN 0-7382-0607-5.
Nilsson, D-E; Pelger S (1994). "A pessimistic estimate of the time required for an eye to evolve". Proceedings of the Royal Society B 256 (1345): 53–58. doi:10.1098/rspb.1994.0048. PMID 8008757.
Nilsson, D. E. (1996). "Eye ancestry: old genes for new eyes". Current biology : CB 6 (1): 39–42. doi:10.1016/S0960-9822(02)00417-7. PMID 8805210.
Zinovieva, R.; Piatigorsky, J.; Tomarev, S. I. (1999). "O-Crystallin, arginine kinase and ferritin from the octopus lens". Biochimica et Biophysica Acta (BBA) - Protein Structure and Molecular Enzymology 1431 (2): 512–517. doi:10.1016/S0167-4838(99)00066-
Scotland, R. W. (2010). "Deep homology: A view from systematics". BioEssays 32 (5): 438–449. doi:10.1002/bies.200900175. Halder, G.; Callaerts, P.; Gehring, W. J. (1995). "New perspectives on eye evolution". Current opinion in genetics & development 5 (5): 602–609. doi:10.1016/0959-437X(95)80029-8.
Halder, G.; Callaerts, P.; Gehring, W. (1995). "Induction of ectopic eyes by targeted expression of the eyeless gene in Drosophila". Science 267 (5205): 1788–92.