Noncontact Binocular Eye-Gaze Tracking for Point-of-Gaze Estimation in Three Dimensions

Binocular eye-gaze tracking can be used to estimate the point-of-gaze (POG) of a subject in real-world 3D space using the vergence of the eyes. In this paper, a novel noncontact model-based technique for 3D POG estimation is presented. The noncontact system allows people to select real-world objects in 3D physical space using their eyes, without the need for head-mounted equipment. Remote 3D POG estimation may be especially useful for persons with quadriplegia or Amyotrophic Lateral Sclerosis. It would also enable a user to select 3D points in space generated by 3D volumetric displays, with potential applications to medical imaging and telesurgery. Using a model-based POG estimation algorithm allows for free head motion and a single stage of calibration. It is shown that an average accuracy of 3.93 cm was achieved over a workspace volume of 30 times 23 times 25 cm (W times H times D) with a maximum latency of 1.5 s due to the digital filtering employed. The users were free to naturally move and reorient their heads while operating the system, within an allowable headspace of 3 cm times 9 cm times 14 cm.