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