We experienced a patient with unilateral visual loss after cervical spine surgery in the prone position. During the initial postoperative period, we were not been able to identify the patient's visual loss because of severe conjunctival edema in both eyes. Three days after surgery, the patient complained of right visual loss and was examined by an ophthalmologist. Ophthalmic artery occlusion was taken to be the presumptive cause, based on fluorescein angiography (FAG) and other evidence. He had several risk factors of ophthalmic artery occlusion, such as; prone position, compression of the eye-balls, anatomic abnormality, cervical spine and a long duration operation, intraoperative bleeding, hypotension and smoking, and a diabetic history. We concluded that attention must always be paid to a patients' eyes throughout the perioperative and postoperative period to prevent such a catastrophic postoperative complication.