Stenosis of the visual field in patients with cerebral infarction is caused by infarction of one of the blood vessels supplying the optic pathway, resulting in narrowing of the visual field. The optic pathway consists of the optic nerve, optic chiasm, optic tract, lateral geniculate body, cortical optic center, and optic radiation. Its blood supply is mainly from the internal carotid artery and the vertebral basilar artery. Among them, the optic cross and optic tract are mainly supplied by the internal carotid artery; the optic radiation is supplied by branches of the vertebral basilar artery and the internal carotid artery together. Therefore, if the cerebral vessels supplying these areas are infarcted, the corresponding visual impairment will occur. For example, infarction of the optic pathway above the optic chiasm can cause ipsilateral hemianopsia in both eyes. Infarcts in the optic tracts can cause symmetrical ipsilateral hemianopsia. If you experience any discomfort such as narrowing of the visual field, seek immediate medical attention and prompt treatment.