Assessment of a Waveguide-based Eye-Tracker

The dissertation describes the feasibility assessment of an holographic waveguide for eye tracking was demonstrated through lab experiments. Waveguides have been recognized as an attractive alternative to other image transmission component in AR and VR applications. In the development of this prototype, a custom-built holographic waveguide (HWG) with photopolymeric in- and out-couplers was employed to convey images of an illuminated eye model to a camera, that were subsequently processed using an off-line Matlab algorithm. A prosthetic ceramic eye model was used for this purpose. The custom-written procedure extracted the parameters relevant to the vector distance of the pupil center from the corneal reflection (CR). The relationship between the components of this vector distance and the relative rotation of the eye in the socket is known from literature to be linear over a wide range of rotations. The benchtop prototype confirmed the linear relationship between eye position and the vector components with a range of 60° degrees (horizontal) and 30° (vertical) with sub-pixel resolution. The system also showed good repeatability of the measure, as the standard deviation of repeated measured is very low (at most 1.2 pixels). This confirms the potential of HWGs for eye tracking applications. The final aim of this discovery would be a light-weight, see-through, wearable eye tracker that could be used both for commercial purposes but most importantly, to help improve current diagnostic techniques for oculomotor disorders (OD).