ObjectiveTo determine whether greater nondominant hand proficiency, or handedness approaching ambidexterity, is associated with better two-handed anterior segment surgical outcomes. DesignRepeated-measures study. ParticipantsOur study included 14 resident physicians from various medical specialties, including ophthalmology, from our academic institution. MethodsThe Eyesi surgical simulator was used to measure the surgical proficiency of 14 resident physicians at our institution on a dominant hand, nondominant hand, and separate bimanual task. The Edinburgh Handedness Inventory (EHI) was used to provide a measure of handedness for each participant. ResultsThe measured parameters were dominant hand, nondominant hand, and bimanual task scores as determined by the Eyesi surgical simulator and gradients of handedness as determined by the Edinburgh Handedness Inventory for each participant. Having greater nondominant hand proficiency did not enhance two-handed surgical outcomes (p = 0.23). Surgical proficiency was greater bimanually compared with use of the nondominant hand alone (median score 74.0 vs 61.0; p = 0.0007), and bimanual and dominant hand surgical performances were not statistically significantly different from each other (median score 74.0 vs 70.5; p = 0.17). ConclusionsOur study shows that having greater nondominant hand proficiency is not a necessary trait for simulated anterior segment surgical aptitude. Two-handed surgical outcomes are directly related to dominant hand surgical performance but less so to the nondominant hand.