DIFFERENCES OF EYE MOVEMENT ON VISUAL INFORMATION PROCESSING BETWEEN YOUNGER AND ELDERLY PERSON

Abstract

In 2005, Japan's aged population (aged 65 and above) reached a historic high of 20,560,000, or 20.04% of the total population, exceeding 20% for the first time. Therefore, the problem of an aging workforce and the influence on society in general cannot be ignored. In particular, the detrimental effect of aging on visual information has led to a rapid rise in the number of traffic accidents involving elderly drivers. Because of this situation, the aim of this study is to clarify the cause of decreased visual function with aging, by considering the difference in visual information processing between younger and elderly persons. Two experiments were conducted in this study. The peripheral visual field was measured to evaluate the region in which objects could be detected. Since the distance from fixation point to the visual object is the intensity of stimulus, the psychometric curve is utilized for the peripheral visual field by statistical estimation using the staircase method. Also in the second experiment, the fixation point and saccadic movement as evaluation indices were measured to examine the visual information processing. The results shows following: (1) It is shown that there is no different in the size of the peripheral visual field between younger and elderly person. (2) The latency of saccadic movement extends as people get older. Also, the accuracy of saccadic movement decreases as people get older. (3) Elderly persons took longer than younger persons to recognize the characteristic of the target.