This paper discusses, first, the selective pressures which led to the two basic types of animal eyes, compound vs. camera eyes. Secondly, it considers what is the significance of the apparent similarity of the wiring patterns in the vertebrate retina and in the optic lobe of the compound eye. No discussion of these matters can be found in the literature since 1915. The present treatment, while it is admittedly only suggestive, is nevertheless open to experimental verification.