What is the main role of CN II: Optic?

The main role of cranial nerve II, also known as the optic nerve, is indeed related to vision. This nerve is responsible for transmitting visual information from the retina in the eyes to the brain. The optic nerve carries signals that are crucial for visual perception, allowing us to interpret light, color, and motion. When light enters the eye, it is converted into electrical signals by photoreceptor cells in the retina, and these signals are communicated via the optic nerve, leading to visual recognition and processing in the brain's occipital lobe.

The other options pertain to different cranial nerves, which are specialized for distinct functions: chewing and biting relate to the trigeminal nerve (CN V), smell is associated with the olfactory nerve (CN I), and facial expressions are controlled by the facial nerve (CN VII). Understanding the specific functions of cranial nerves helps clarify the specialized roles they play in sensory and motor functions of the body.