Accommodation, convergence and pupil constriction, which are called near triad, usually respond simultaneously at near reflex in natural view condition, but no research has been made on how pupil behaves following artificial near vision generated by binocular parallax.
Laboratory experiments were conducted on several subjects, to examine eye movement and papillary response under artificial binocular parallax, by using Eye-Sensing Head Mounted Display (ES-HMD). The ES-HMD can monitor the user's both eyes and calculate ocular information such as pupil size, eyeblink or eye movement, while presenting visual stimulus to his both eyes.
It was found that pupil constricts according to the increase of binocular parallax and vise versa, for the case of vergence normal subjects who have an ability of adaptation to binocular parallax, while conjugate eye movement instead of vergent eye movement appeared for the case of vergence anomaly subjects who would not succeed in binocular fusion. It was also found for a vergence normal subject that continuous periodic pupillary movement of constriction and dilation has tendency of hysteresis, which is caused by different muscle organ between constriction and dilation. Another results also suggest that the direction of smooth pursuit eye movement in a vergence anomaly under binocular parallax depends on the dominant eye.
