Final answer:
The posterior portion of the eyeball is comprised of the retina, optic nerve, and optic disc, with each part playing a crucial role in vision. O optic nerve
Step-by-step explanation:
The parts that make up the posterior portion of the eyeball include the retina, the optic nerve, and the optic disc. The retina is the light-sensitive lining found at the back of the eye. It is where the conversion of light images into electrical signals occurs, thanks to the photoreceptor cells known as rods and cones.
The optic nerve is crucial as it transmits these signals from the retina to the brain, allowing us to process the visual information. The optic disc, mentioned as a circular area at the back of the eye where the optic nerve connects to the retina, is the point of exit for ganglion cell axons leaving the eye.
Due to the absence of photoreceptor cells, it creates a blind spot in our visual field. The nerve impulses from the rods and cones travel to the optic nerve via the optic disc, ensuring that visual information reaches the brain.