Stereo Eye Tracking with a Single Camera for Ocular Tumor Therapy

We present a compact and accurate stereo eye tracking system using only one physical camera. The proposed eye tracking system is intended as a navigation system for ocular tumor therapy. There, the available physical space to mount an eye tracker is limited. Furthermore, high system accuracy is demanded. However, high eye tracker accuracy and system compactness often disagree. Current established eye trackers can live with that compromise, desktop devices focus more on accuracy whereas mobile devices focus on compactness. We combine a stereo eye tracking algorithm with a clever arrangement of two planar mirrors and a single camera to get high accuracy, precision and a compact design altogether. We developed an eye tracking prototype and tested the system with ten healthy volunteers. We show that the proposed eye tracker is more accurate and robust, while at the same time equally compact as a comparable eye tracking system containing one instead of two mirrors.