A Limbus-Based Approach for Eye Gaze Trackers

Eye gaze trackers have numerous applications in medicine, gaming, advertising, teaching and learning, intelligent transportation, etc. In this paper, we proposed a novel approach for video based eye gaze trackers. In this approach, we apply the circumcircle of triangle principle to the limbus part of human eyes. First, an image pre-processing step is used to find three triangle vertices located on limbus. Then, we use the coordinates of these points to determine the limbus center using the circumcircle of triangle principle. Furthermore, when the proposed system fails to find the three useful points on limbus of one eye, a mirror procedure is adopted to find its limbus center based on the information extracted from the other eye. The proposed method can solve the occlusion problem caused by the eyelids that cover part of limbus. The experimental results show that the average eye detection rate is 98.39% and the average error between estimated and actual centers of limbus is only 1.99 pixels. The proposed method is simple, fast, and effective.