"Cerebrovascular disorders commonly have neuro-ophthalmologic manifestations. Some of these disorders are characterized by impaired blood flow through normal or damaged blood vessels, others by leaking ofblood or its components through the walls ofsuch blood vessels. Still other disorders result from inappropriately increased blood flow through congenitally abnormal vessels or vessels that have been damaged by injury or disease. In most ofthese cases, the abnormal blood flow or leakage causes hypoxia, ischemia, infarction, hemorrhage, or a combination ofthese processes, thus damaging cerebral, orbital, or ocular tissue and causing disturbances ofneuro-ophthalmologic significance. The seven chapters that comprise this section are concerned with the major vascular conditions that produce neuro-ophthalmologic manifestations."