so we have this situation: naturalism is propounding the idea that without a blueprint, that the eye was assembled, likewise the brain; each assembled independent of the other. then the idea came up - that it would be good to connect them with an optic nerve. then some backing and filling took place to get the focus correct. in the meantime, it was decided that chemicals and blood would be needed to supply the energy and that was hook-up.
Atheist Credo: An universe by chance that also just happened to admit the observer by chance.