Abstract: A gaze-tracking method and system are disclosed that employs gaze rays generated from measured/tracked eye movements and fixation for interaction with objects and environment within a three-dimensional computing environment. The gaze ray is tracked to provide measures of ocular control, fovea control, and/or associated neural pathways in which the measures can be then used for one or more physiological assessments of the user, including, for example, eye dominance determination, vestibular assessment, visual fixation assessment, optokinetic assessment, smooth pursuit assessment, nystagmus quick phase assessment, saccades assessment, and vergence assessment.