Core Viewpoint - The eyes serve as a "monitor" for brain diseases, particularly for conditions like cerebral infarction, which has high recurrence, disability, and mortality rates [1][2][3] Group 1: Connection Between Eyes and Brain - The optic nerve is a direct extension of the brain, and the anatomical structure of the eye's blood vessels is similar to that of the brain's blood vessels [1][3] - Changes in the eye can reflect underlying brain conditions, as the eye and brain share a common blood supply system [3] Group 2: Warning Signs of Cerebral Infarction - Approximately 20%-50% of patients with cerebral infarction may exhibit significant eye abnormalities prior to the onset of the condition [2] - Four specific eye symptoms may indicate a risk of cerebral infarction: - Sudden blackening of vision in one eye [4] - Loss of vision in the same side of both eyes [4] - Double vision [4] - Nystagmus, which can indicate cerebellar or brainstem infarction [5] Group 3: Recommended Actions for Eye Symptoms - If eye symptoms are occasional, patients should first consult an ophthalmologist to rule out eye diseases [6] - For sudden or recurrent eye symptoms accompanied by dizziness or speech difficulties, immediate consultation with a neurologist or emergency department is advised [6] - Timely treatment within 4.5 hours of symptom onset significantly increases recovery chances for cerebral infarction [6]