Infantile-onset saccade initiation delay (ISID), commonly known as congenital ocular motor apraxia, is characterized by difficulty in triggering horizontal volitional saccades. It typically presents with head thrusts in infancy and is often associated with developmental delay. Patients with ISID are reported to have abnormalities in various brain regions including the corpus callosum, brainstem, and cerebellum. We propose that ISID is caused by the disruption or disconnection of axons linking analogous brain regions involved in processing saccades across the two sides of the brain or bilateral damage to these regions.