Characteristic of depth attention when observer is in dark field under supposed traffic environment

The numbers of people, who have access to their driving license, is getting more and more. Hereinto, elderly drivers and drivers with low vision were increasing in recent years. However, traffic accidents involving elderly drivers have been rapidly increasing. When the lens of eye becomes yellowier, less light entering the eye of driver reaches the photoreceptor, thereby, vision of drivers is in a dark field state. It is the purpose of this paper to investigate depth attention characteristic of drivers when drivers are in dark field in the traffic environment by the use of a semi-realistic setting-a three-dimension (3-D) attention measurement system. A special test eyepiece, there was a yellow plastic film in front of eyepiece, have been fabricated, it can simulate the dark field or low vision. The experiments were conducted in order to examine characteristic of attention of drivers who are in dark field. In the experiments, three kind of ambient illumination condition were used: daylight condition, dawn condition and twilight condition. In each experiment, there were three kinds of cue condition: valid, invalid and neutral condition. Reaction time has been considered. The characteristic of depth attention of drivers who are in dark field is discussed. This paper compared the experimental results of younger drivers in dark field with experimental results of elderly drivers. The results show that (1) the peripheral luminance had evident influence on the reaction time, reaction time was slow in dawn and twilight condition than in daylight condition, (2) the reaction time of elderly observers was slow than younger observers in dark field.