Which cranial nerve should be assessed for vision?

The optic nerve is the cranial nerve responsible for vision, making it the correct choice for this question. It transmits visual information from the retina in the eyes to the brain, allowing for the perception of sight. Assessment of the optic nerve typically involves testing visual acuity and peripheral vision, which are essential components of a comprehensive visual examination.

The other cranial nerves, while related to eye movement and coordination, do not primarily serve the function of vision. The oculomotor nerve is involved in controlling most of the eye's movements and adjusting the size of the pupil, the trochlear nerve also controls a specific eye muscle for movement, and the abducens nerve is responsible for lateral eye movement. However, none of these are directly responsible for transmitting visual information, which is why the optic nerve is the focus when assessing vision.