It has been reported that postoperative vision loss after lumbar surgery is increasing. It is an uncommon but devastating complication. One of the risk factors that has been reported is increased intraocular pressure (IOP), which may decrease perfusion pressure to the optic nerve. Intraocular pressure in anesthetized, prone spine patients has been studied with the head in neutral position. The prone position and duration of the procedure did increase the IOP. Our hypothesis is that adjusting the position of the head in space will alter the intraocular pressure, with an extended position decreasing IOP. This study is a, randomized, controlled design: neutral head position (standard care) or extended head position (intervention group). Patients who qualify for spinal fusion surgery and meet the inclusion criteria will be randomized to either the neutral (standard practice) or the intervention group.Randomization of patients will be computer generated.