Postoperative visual loss (POVL) is a rare but catastrophic complication of spine surgery. The extremely low incidence has made its study and prevention a challenge for neuroanesthesiologists. This chapter presents a case study of a 62-year-old female who presented for a revision L4-5 foraminotomy and L4-S1 transverse lumbar interbody fusion. There are multiple causes of POVL, including cortical infarction, direct injuries to the eye and ischemic injuries to the retina and optic nerve. The most common permanent injuries are ischemic in nature including central retinal artery occlusion (CRAO) and ischemic optic neuropathy (ION). Many risk factors have been proposed yet understanding of the etiology of ION remains inadequate. Until we have a better understanding of these risk factors, careful attention to the eyes, staged procedures, vigilance with regard to intraocular pressure and the optimization of oxygen-carrying capacity are the best preventative measures available.