The tests being investigated measure: 3D vision (i.e. gross stereoscopic acuity), uniform movement of the eyes (i.e. "motor punctum proximum"), ability of the eyes to adapt to a target moving towards and/or away from the eyes (i.e. binocular fusion with convergence and divergence), quick movements of the eyes (i.e. saccadic movements), natural alignment of the eyes (i.e. anatomic oculomotor deviation), and double vision as a target is moved towards the eyes (i.e. convergence fusional proximum).