A comb-like structure of blood vessels belonging to the choroid in the eye of a bird or reptile. It is non-sensory and is a pigmented structure that projects into the vitreous body from the point where the optic nerve enters the eyeball. The pecten is believed to both nourish the retina and control the pH of the vitreous body. [ http://en.wikipedia.org/wiki/Pecten_oculi ]