title: Optics of the human cornea influence the accuracy of stereo eye-tracking methods: a simulation study.
abstract: Current stereo eye-tracking methods model the cornea as a sphere with one refractive surface. However, the human cornea is slightly aspheric and has two refractive surfaces. Here we used ray-tracing and the Navarro eye-model to study how these optical properties affect the accuracy of different stereo eye-tracking methods. We found that pupil size, gaze direction and head position all influence the reconstruction of gaze. Resulting errors range between ± 1.0 degrees at best. This shows that stereo eye-tracking may be an option if reliable calibration is not possible, but the applied eye-model should account for the actual optics of the cornea.
authors.affiliation: Radboud University Medical Centre Nijmegen, Donders Institute for Brain, Cognition and Behaviour, Department of Cognitive Neuroscience, P.O. Box 9101, 6500 HB, Nijmegen, The Netherlands.
authors.forename: A D
authors.initials: AD
authors.lastname: Barsingerhorn
authors.affiliation: Radboud University Medical Centre Nijmegen, Donders Institute for Brain, Cognition and Behaviour, Department of Cognitive Neuroscience, P.O. Box 9101, 6500 HB, Nijmegen, The Netherlands; Bartiméus, Institute for the Visually Impaired, Van Renesselaan 309, 3703 AJ, Zeist, The Netherlands.
authors.forename: F N
authors.initials: FN
authors.lastname: Boonstra
authors.affiliation: Radboud University Medical Centre Nijmegen, Donders Institute for Brain, Cognition and Behaviour, Department of Cognitive Neuroscience, P.O. Box 9101, 6500 HB, Nijmegen, The Netherlands.
authors.forename: H H L M
authors.initials: HH
authors.lastname: Goossens
keywords: (330.2210) Vision - eye movements; (330.4460) Ophthalmic optics and devices; (330.7326) Visual optics, modeling