Ocular ischemic syndrome (OIS) is a disease seen in cardiology, ophthalmology, neurology, and neurosurgery, which can lead to brain and ocular symptoms induced by carotid artery obstruction or stenosis. In local and general manifestation, ocular symptoms usually appear first. Ocular symptoms show the prewarning effect of other ischemic damage. Ophthalmologists should pay attention to the clinical manifestation and damages of OIS. The establishment of multidisciplinary diagnosis and treatment patterns for OIS is a pivotal issue for several disciplines.