Visual fatigue during VDT work: Effects of time-based and environment-based conditions

This study attempts to demonstrate the respective effects of time-based and environment-based factors in visual fatigue and task performance for a dynamic VDT work. Two experiments were conducted in the current study. Experiment 1 involved 10 participants tracking a scanning line at two different scanning speeds, and responding to a designated target presented singly at two different temporal frequencies. Experiment 2 involved 10 participants tracking a target with changing screen type and viewing distance. The observation results indicated that scanning speed, target presentation rate, and work period (time-based factors) significantly affected visual acuity, critical fusion frequency (CFF) and accommodative power. Screen type and viewing distance (environment-based factors) also had a significant main effect on visual acuity, CFF, accommodative power, and reaction time. This study concluded that time-based and environment-based factors influence operator visual fatigue and task performance during dynamic VDT work.