Our pilot study suggested that while fixating on a stationary object binocularly, each line of sight of the two eyes does not always go directly toward the object. Therefore, we experimentally investigated the amount of the displacement of the pupil center while the fixation point was changed transversally. The subjects were instructed to fixate on three targets arranged horizontally with intervals of nine degrees. The distance from the subject to the targets was any of 0.5 m, 1.0 m and 1.5 m. A significant difference of the amount of the displacement of the pupil center was observed relative to the fixation distance. The positions of the node of the line of sight, which provide no relationship between the fixation distance and the pupil center displacement, were calculated. The node of the line of sight of the non-dominant eye was nearer to the fixation panels than that of the dominant eye. Considering this, such a node would be effective for the precise measurement of gazing point.

We developed a stereoscopic video system, which has high-resolution images for central vision and it is called the Q system. The Q system uses a compound image that is a wide-angle image with an embedded high-resolution image. However, the Q system could not be used under situations where many robots work at the same time. This is because it needs four channels of video signals and the available channels could be limited under such situations. Thus, we have developed a digital Q system. The system can be used under such restricted situations, because the required data transfer rate is adjustable by changing the compression rates for a high-resolution image and a wide-angle image. In addition, an experiment confirmed that even though the systems used the same data transfer rate, digital Q system could make teleoperation more efficient and more precise than a conventional stereoscopic video system.