Incidence estimates for postoperative vision loss after nonocular surgery range from 0.013% for all surgeries up to 0.2% following spine surgery. The most common neuro-ophthalmologic causes of postoperative vision loss are the ischemic optic neuropathies (IONs), either anterior or posterior.This complication of case reports suggests that a combination of prolonged surgery in the prone position, decreased ocular perfusion pressure, blood loss and anemia/hemodilution, and infusion of large quantities of intravenous fluids are some of the potential factors involved in the etiology of postoperative ION. The specific pathogenesis and risk factors underlying these neuro-ophthalmic complications remain unknown, and physicians should be alert to the potential for loss of vision in the postoperative period. We report the only cases of ION after carotid body tumor resection in the literature and review current theories regarding the etiology and diagnosis of vision loss.