Which cranial nerve is responsible for the sensation of sight?

The optic nerve is specifically responsible for the sensation of sight. It transmits visual information from the retina in the eye to the brain, facilitating the perception of images. When light enters the eye, it is focused onto the retina, where photoreceptor cells convert light into electrical signals. These signals are then carried by the optic nerve to the visual cortex of the brain for processing, enabling the interpretation of what we see.

The other cranial nerves mentioned have different functions. The oculomotor nerve primarily controls most of the eye's movements and is responsible for adjusting the lens and pupil to control the amount of light entering the eye, but it does not directly involve sight sensation. The trochlear nerve is involved in the movement of the superior oblique muscle of the eye, which also does not pertain to sensory input. The trigeminal nerve, while responsible for sensation in the face and certain motor functions, does not play a role in vision. Thus, the correct choice is the optic nerve, as it is uniquely dedicated to the function of vision.