Structure of the Human Eye
Cornea
   protects eye
   refracts light
Iris
   colored muscle
   regulates pupil size
Pupil
   regulates light input
Lens
   focuses images on retina
Ciliary Muscles
   controls shape of lens
   accomodation
Fovea
   point of central focus
   contains most cones
   birds of prey/rodent variation
Retina
   contains photoreceptors