Abstract
The effects of character luminance on physiological strain were experimentally studied in a visual search task, which set subjects looking closely at a CRT display. Five healthy male subjects performed the task for two hours. Character luminances of 5cd/m2, 24cd/m2 and 50cd/m2 were evaluated. Near point accommodation, visual acuity, flicker value (CFF), electroencephalogram (EEG), blinking rate, reaction time and error rate were measured and physical symptom questionnaires were filled out.
Near point accommodations of three luminance conditions were all significantly increased by 2-hours VDT task. Increased in near point at 5cd/m2 were tended to be largest in three conditions. At 5cd/m2, flicker value was significantly and blinking rate was kept lower than at any other luminance condition during VDT task. Reaction time and error rate at 5cd/m2 were largest in three conditions. Reaction time was significantly smaller at 24cd/m2 than at any other condition. Blinking rate and reaction time showed quadratic regression curves with luminance. Error rate was linearly correlated with luminance. The results of this study suggested that a proper luminance was at about 30cd/m2.
