Sample and Setting Patients included will be children age 3 through 10 years scheduled for strabismus surgery. The procedure may also include scheduled exam under anesthesia (EUA) of the eyes, but any other surgical procedure in conjunction with strabismus will be excluded from enrollment. Review of anesthesia records shows that 480 patients met inclusion criteria for the preceding 12 months. The primary outcome measure is pain as measured by the revised Faces, Legs, Anxiety, Cry & Consolability scale (rFLACC). Based on previous pilot work, the investigators expect pain scores to have a mean of five and a standard deviation of two. The goal is to detect a change of one point in rFLACC scores, which the investigators believe would be clinically significant. With alpha of 0.05 and power of 0.80, the investigators would need 64 patients in each arm for a one point decrease in rFLACC scores to be statistically significant. The investigators expect that ten percent of patients will have to be dropped because of missing data, so the investigators are proposing to enroll 71 patients in each arm (142 patients total) in order to have data for 64 patients in the analyses.