a.Light energy strikes the retina and excites pigments to release retinal.
b.Light energy strikes the cornea and excites pigments to release retinoic acid.
c.Visual pigments deep in the brain are excited by light transmitted through the retina.
d.Epithelial cells on the surface of the eye respond to light energy by transmitting opsin molecules along nerve pathways to the brain.
e.Retinal in the visual cortex responds to electrical signals from the retina.