Asthnopia in visual display teminal (VDT) work differing in working speed and display color

Normal subjects underwent a loaded experimental visual calculating task on a display screen differing in working speed and display color. Accuracy of the task in these conditions and saccadic reaction time with a negative display unit in different working speed were measured wvery 10 minutes during the task. As a result, no significant changes of accuracy of the task were found in these conditions. In the time course of changes, however, it was found that saccadic reaction time was prolonged significantly within 40 minutes after loading, continuing until the end of the task. These results suggested that visual afferent system was deteriorated by VDT work and prolonged saccadic reaction time had relation to the onset of a asthenopia.