A system and method for measuring eye movement and/or eye position and postural sway of a subject is disclosed herein. The system generally includes an eye movement tracking device, a postural sway detection device, and a data processing device operatively coupled to the eye movement tracking device and the postural sway detection device. During the execution of the method, the eye movement and/or eye position of the subject is measured using the eye movement tracking device, and the postural sway of the subject is measured using the postural sway detection device. A method for determining a gaze direction of a subject during a balance test and/or concussion screening test, and a method for assessment of a medical condition of a subject are also disclosed herein.