Fixation distance estimation using vergence eye movement for automatic focusing glasses

In this study, we propose a method for estimating fixation distance on the basis of measurements of vergence eye movements. The aim of this approach is to control the lens focus of automatic focusing glasses. To reduce user effort at the time of calibration, the calibration was performed at infinite distance gazing, and the parameters were determined from the premeasured pupillary distance at infinity and iris diameters. To clarify the effectiveness of the proposed method, we conducted evaluation experiments using prototype glasses. The results showed that even participants requiring myopic correction could perform accurate motion vergence movements. Fixation distance estimation showed that, with the eye calibrated at infinite distance gazing, shorter distances could be estimated with an average accuracy exceeding 90%.