Final answer:
The nerve impulse from light sensation starts at the rods and cones in the retina, moves to the retinal ganglion cells, travels through the optic nerve to the optic chiasm, continues as the optic tract to the lateral geniculate nucleus, and ultimately reaches the visual cortex in the brain for perception.
Step-by-step explanation:
The process of conducting a nerve impulse from the eyes to the brain involves several key steps. Firstly, light enters the eye and is focused on the retina by the lens. The retina, which houses photoreceptor cells known as rods and cones, converts light into electrical signals. These signals are then transmitted to the optic nerve via the optic disc.
Rods and cones are connected to retinal ganglion cells (RGCs). Axons from these cells converge to form the optic nerve. The optic nerve carries visual information to the optic chiasm, where some of these nerve fibers cross to the opposite side. From the optic chiasm, the nerve impulse continues as the optic tract. The lateral geniculate nucleus of the thalamus receives these impulses and then relays them to the visual cortex in the occipital lobe of the brain, where visual perception occurs. Through this complex pathway, including the magnocellular and parvocellular pathways, the brain receives and processes visual information, allowing us to see.