Final answer:
The trochlear nerve is responsible for eye movement via the superior oblique muscles.
Step-by-step explanation:
The trochlear nerve is responsible for eye movement via the superior oblique muscles. The trochlear nerve controls the superior oblique muscle, which rotates the eye along its axis in the orbit medially, a movement called intorsion.
The other extraocular muscles, including the lateral rectus muscle responsible for abduction of the eye, are innervated by the oculomotor nerve. The motor nuclei of these cranial nerves are connected to the brainstem, which coordinates eye movements.