Visual performance and fatigue in reading vibrating numeric displays

There is increasing use of LCD displays in vehicles and aircrafts. The reading performance of these displays is subject to vibration. Under a software simulated vibrated environment, the study investigated the effect of vibration on visual performance and fatigue for several numerical display design characteristics including the font size and the number of digits displayed. Visual performance and fatigue while identifying the displayed numbers were measured with the reaction time, accuracy, critical Flicker fusion frequency, visual acuity, and subjective evaluation. Both the frequency and magnitude of vibration had significant effects on the reaction time, accuracy, and visual fatigue. Horizontally presented numbers were affected more under horizontal vibration than under vertical vibration. The results showed that whenever the display is used in vibration environment, an increased font size may be an effective way to compensate the adverse effect of vibration.