[Oculomotor system and multiple sclerosis]. 
Disorders of ocular motility due to multiple sclerosis can cause significant symptoms, such as blurred vision, diplopia, oscillopsia and dizziness.  The spectrum of ocular motor disorders is broad due to the multifocal nature of the disease.  The most frequent disorders include dysmetric saccades, impaired smooth pursuit, internuclear ophthalmoplegia (INO), impaired vestibulo-ocular reflex, misalignment of visual axes, impaired vergence and gaze-evoked nystagmus.  Patients with abnormal eye movements are more handicapped than patients without ocular motility disorders as eye movement disorders and gait disturbances are both caused by an extensive involvement of the brainstem and cerebellum.