Effect of acute eye fatigue on cognition for young females: a pilot study.

The number of people suffering from eye fatigue induced by visual display terminal (VDT) viewing is expected to increase in the modern world. Eye dysfunction is suggested to induce a decrease in cognitive function, at least in the long term. Furthermore, considering other previous findings, it may be reasonable to think that acute or relatively short-term eye dysfunction attenuates cognitive function for not only older but also young individuals. Hence, clarification of the effect of eye fatigue induced by VDT viewing on cognitive performance is essential in order to maintain and/or improve our quality of life in the modern world regardless of age. The present study investigated the effect of eye fatigue induced by 1-h VDT viewing on cognitive performance, to test the hypothesis that such eye fatigue impairs cognitive performance in young individuals. A total of 19 healthy female university students voluntarily participated in this study. Before and after the 1-h VDT viewing or resting, the degree of eye fatigue and cognitive performance were evaluated. Refractive error measurement was performed to assess the degree of eye fatigue using a binocular auto refractometer, and a memory recognition task and Go/NoGo task were used to estimate cognitive performance. Response accuracy and reaction time were evaluated in the two tasks. Due to difficulty in interpreting the data of refractive error for one participant from the perspective of eye fatigue, the data for 18 participants were used for further analysis. The refractive error was significantly lower after than before the VDT viewing, but a corresponding change was not found before and after resting. Regarding cognitive performance, only the reaction time in the memory recognition task varied with the VDT viewing or resting. The reaction time was significantly longer after than before resting, without a corresponding difference before and after the VDT viewing. Thus, the 1-h VDT viewing induced eye fatigue, but relatively improved rather than attenuated reaction time in the memory recognition task. These results suggest that the effect of the increase in arousal level induced by the present VDT viewing on memory recognition compensated for the negative effect of 1-h resting of the eyes. We conclude that the acute eye fatigue induced by the 1-h VDT viewing does not have detrimental effects on cognition in young females at least under the present conditions.