Effectiveness of Eye-Gaze Input System : Identification of Conditions that Assures High Pointing Accuracy and Movement Directional Effect

The condition under which high accuracy is assured when using an eye-gaze input system was identified. It was also investigated how direction of eye movement affected the performance of an eye-gaze input system. Here, age, the arrangement of targets (vertical and horizontal), the size of a target, and the distance between adjacent rectangles were selected as experimental factors. The difference of pointing velocity between a mouse and an eyegaze input system was larger for older adults than for young adults. Thus, an eye-gaze input system was found to be effective especially for older adults. An eye-gaze input system might compensate for the declined motor functions of older adults. The pointing accuracy of an eye-gaze input system was higher in horizontal arrangement than in vertical arrangement. The distance between targets of more than 20 pixels was found to be desirable for both vertical and horizontal arrangements. For both the vertical and horizontal arrangements, the target size of more than 40pixels led to higher accuracy and faster pointing time for both young and older adults. For both age groups, it tended that the pointing time for the lower direction was longer than that for other directions