Retinal artery occlusion is a condition where one of the arteries supplying blood to the retina becomes blocked. This blockage can lead to sudden vision loss in the affected eye, as the retina requires a constant blood supply to function properly. The occlusion can be caused by various factors, including blood clots, high blood pressure, or other underlying health issues. Symptoms of retinal artery occlusion may include a sudden decrease in vision or a shadow in the visual field. Diagnosis typically involves a comprehensive eye examination, and treatment options may vary depending on the severity and cause of the occlusion. Early intervention is crucial to prevent permanent vision loss.