Which cranial nerve is responsible for vision?

The optic nerve, also known as cranial nerve II, is specifically responsible for vision. It transmits visual information from the retina in the eye to the brain, where the information is processed to form images. This nerve plays a crucial role in the visual pathway, enabling the perception of light, color, and motion. Any damage or dysfunction in this nerve can lead to significant visual impairment or blindness.

The other cranial nerves mentioned are involved in different functions: the olfactory nerve is responsible for the sense of smell, the oculomotor nerve controls most of the eye's movements as well as the constriction of the pupil, and the trigeminal nerve is primarily responsible for sensation in the face and motor functions such as biting and chewing. Thus, the optic nerve’s dedicated function in vision distinguishes it from the others.