A gazing point distance detection system for accommodation assisting glasses

Proposes a gazing point distance detection system which is one of the important key issues in order to realize accommodation assisting glasses, automatic focusing glasses which can assist eye focusing for aged persons who suffer from presbyopia. The new system has a tunnel type light path device which consists of very narrow tunnels with the opening of a vertically long rectangle. The tunnels are arranged horizontally on the photosensitive device which is located in front of each eye and embedded in the glass. By this structure, this device can detect the light from one horizontal position only on the eye at the corresponding position on the photosensitive device. Therefore, the center of gravity of iris for each eye can be detected, and then the horizontal direction of line of sight can be calculated. As the photosensitive device, we propose dark image position sensitive device (D-PSD). A prototype system using the tunnel type light path device has been manufactured experimentally. From the result of experiments for evaluating detecting characteristics, it was confirmed that proposed technology in this study was useful for realization of the accommodation assisting glasses for presbyopia.