Step 1: Recall the parts of the human eye and their functions. Optic nerve: Transmits visual information to the brain. Retina: Contains photoreceptor cells (rods and cones) that detect light. Pupil: Controls the amount of light entering the eye. Cornea: Refracts light entering the eye. Step 2: Identify the light-sensitive membrane. The retina is the layer of the eye that contains the light-sensitive cells (photoreceptors).