CADASIL is an inherited disease of the small arteries of the brain caused by mutations in the NOTCH3 gene. The article describes a rare case of a young man with CADASIL who simultaneously developed visual dysfunction and cerebral infarction. Cerebral infarction was confirmed by magnetic resonance imaging. Symptoms of acute vision loss arose as a result of ischemia of the optic nerve and retina. This case demonstrates the association between ocular hemodynamics and hereditary small vessel disease of the brain. It is important to consider secondary causes in nonarteritic anterior ischemic optic neuropathy (NAION) and retinal hypoperfusion in a young patient with no other risk factors. These manifestations may signal CADASIL.