Eye-movement Detection System using High-speed Tracking for Non-contact Microsaccade Detection

Abstract

A conventional high-precision system for measuring microsaccadic eye movements requires a participant’s head to be fixed to maintain measurement accuracy. Therefore, it is difficult to observe microsaccades under psychologically natural situations because the contact measurement is a burden on the participant. We propose an eye-movement detection system that involves the following two methods. The first method is for non-contact measurement that combines a coarse eye position based on face detection from wide-angle images and high-precision optical eye-tracking-control information based on retro-reflected eye images from a high-speed zoom camera. The second method is for detecting microsaccades by removing the head-motion component from the eye-position information in an image in which the head motion and eye movement are mixed. Experiments using an eye model that can reproduce microsaccadic movements at any time confirmed that our system maintained high precision of the gaze-angle estimation, which enables microsaccade measure in a wider area compared with a conventional system and detected microsaccades of the eye model with 0.2-degree amplitude even when the model base moved at 20mm/s.