Pointing by gaze, head, and foot in a head-mounted display

This paper presents a Fitts' law experiment and a clinical case study performed with a head-mounted display (HMD). The experiment compared gaze, foot, and head pointing. With the equipment setup we used, gaze was slower than the other pointing methods, especially in the lower visual field. Throughputs for gaze and foot pointing were lower than mouse and head pointing and their effective target widths were also higher. A follow-up case study included seven participants with movement disorders. Only two of the participants were able to calibrate for gaze tracking but all seven could use head pointing, although with throughput less than one-third of the non-clinical participants.