A case of anterior ischemic optic neuropathy (AION) associated with 90% stenosis of the ipsilateral internal carotid artery (ICA) and diminished blood flow through the ophthalmic artery was studied. After carotid endarterectomy (CEA), the patient showed subjective and measurable improvement in vision and increased ophthalmic artery flows. This observation supports the role for screening carotid duplex scanning and transcranial Doppler in patients with AION. Early CEA in patients with associated ipsilateral ophthalmic artery hypoperfusion may improve visual outcome.