Visual cognitive performance of elderly people: effects on reading time of age, character size and visual distance

In this study, we conducted two experiments on visual cognitive performance in reading an on-board information device. Experiment 1: The relation between the gazing time needed for reading and the number of Kanji characters displayed was investigated, as the number of characters was changed in three steps. The gazing time was divided into preparation time and information processing time. The unit information processing speed was calculated from the amount of information read divided by the information processing time. Experiment 2: The character size was changed between three conditions (large, middle and small), and visual distance was changed between two conditions (700 and 2000 mm). The gazing time was similar to that in experiment 1. The results from these experiments are applicable to the design of user-friendly information devices, taking into account the user’s age.