Which cranial nerve is responsible for controlling lateral eye movement?

The cranial nerve responsible for controlling lateral eye movement is the sixth cranial nerve, also known as the abducens nerve (CN VI). This nerve specifically innervates the lateral rectus muscle, which is one of the extraocular muscles that allows the eye to move outward, away from the midline of the body. Proper function of the abducens nerve is crucial for coordinated horizontal eye movements, allowing for clear and stable vision while tracking objects.

In contrast, other cranial nerves mentioned in the options have different roles in eye movement. The optic nerve (CN II) is primarily responsible for vision, transmitting visual information from the retina to the brain. The oculomotor nerve (CN III) controls most of the eye's movements, as well as the constriction of the pupil and maintaining an open eyelid. The trochlear nerve (CN IV) innervates the superior oblique muscle, which serves a role in downward and inward eye movement.

Understanding the specific functions of these cranial nerves helps clarify the essential role of the abducens nerve in facilitating lateral eye movement, making it the correct choice.