Bright-pupil microsaccadic artificial eyes with optical gaze visualization

Artificial eyes that mimic the human eyes are used to develop humanoid robots and to evaluate the accuracy of eye trackers. However, conventional artificial eyes have issues in reproducing fast movements such as saccades. In this paper, we propose artificial eyes that can generate microsaccadic motion, have retroreflective bright pupils, and have an optical design that optically visualizes their gaze direction. The eye rotation is reproduced by a high-speed galvano motor, and the bright pupil is reproduced by a sand-surface plano-convex lens and retroreflective material, respectively. A laser light source and a prism mirror are placed on the rotational axis to enable optical gaze visualization while maintaining the light weight required for fast rotation. Evaluation experiments confirmed the appearance quality of the bright pupil and gaze visualization, quantitatively evaluated the responsiveness of the microsaccadic motion, and showed the performance of gaze measurement and microsaccade detection in a commercial eye tracker.