When changing focus, conjugate eye movements allow for the perception of a stabilized world relative to an individual, rather than the perception of the world “jumping” as the individual’s gaze shifts.
Horizontal conjugate gaze is controlled by the nuclei of the Ocular Nerve, CN III, and the Abducens nerve, CN VI, the paramedian pontine reticular formation, and the nucleus prepositus hypoglossi-medial vestibular nucleus.
Vertical conjugate gaze is controlled by the nuclei of CN III and the Trochlear nerve, CN IV, the rostral interstitial nucleus of medial longitudinal fasciculus (riMLF), and the interstitial nucleus of Cajal.
[3][4] Disorders of conjugate gaze typically consist of the inability to move one or both eyes in the desired direction, or the inability to prevent eyes from making vergence movements.
[5] Internuclear ophthalmoplegia: Internuclear ophthalmoplegia affects horizontal gaze, such that one eye is capable of full horizontal movement, while the other is incapable of gazing in the direction contralateral to the affected eye.