Visual fatigue following long-term visual display terminal work under different light sources

Abstract

Although visual display terminals have been used in office work for many years, research on the effect of long time work using them is still insufficient. Also, the impact of a LED light source for all day work is not clear. In this paper, the visual fatigue caused by long-term VDT work under fluorescent and LED luminaires was investigated though subjective reports of symptoms, ophthalmological parameters and physiological signals. The results show that visual fatigue becomes more serious with increasing time spent at VDT work. Compared to fluorescent luminaires, the LED luminaires produced significantly greater near point accommodation, blink amplitude and oxygen saturation but less dry eye symptoms, less best corrected distance visual acuity and less high-frequency electrocardiogram power as time passed, although all were of small effect size. Although the participants carried out eight hours of VDT work under the two light sources, at the end the symptom ‘tired eyes’ was rated as moderate while all the other reported symptoms were rated as slight.

Assessment of visual fatigue under LED tunable white light with different blue components

“…Thus, only using subjective evaluation methods may not supply all necessary and accurate information. Ophthalmological parameters directly reflecting vision function were proved to be good indexes that reflect visual fatigue according to our previous study . Moreover, psychophysiology is concerned with physiological bases of perceptual and cognitive processes.…”

“…Ophthalmological parameters directly reflecting vision function were proved to be good indexes that reflect visual fatigue according to our previous study. 12 Moreover, psychophysiology is concerned with physiological bases of perceptual and cognitive processes. Physiological measurement methods mainly consist of two categories referring to two neural systems: central nervous system (CNS) and autonomic nervous system (ANS).…”

7.4: Visual Fatigue during Viewing High‐Dynamic Range Display

“…They were 8 female and 8 male graduate students, with ages ranging between 22 and 27 (Mean=24). All met the optometric screening criteria [3] and had corrected to their best visual acuity.…”

“…Based on our previous paper [3] , the subjective questionnaire consisting of 9 symptoms with a 5-point scale (1 = none, 2 = slight, 3 = moderate, 4 = obvious, 5 = severe) was used. The symptoms included tired eyes, sore or aching eyes, irritated eyes, dry eyes, hot or burning eyes, double vision, blurred vision, dizzy and headache.…”

“…It is not only associated with the performance of visual system, but also correlates with nervous system. Thus, the various indicators from each aspect of subjective questionnaire, ophthalmological parameters and physiological signals are used together to study visual fatigue to enhance the estimation accuracy [3] .…”