Effects of difference of spectral power distribution on visual fatigue: Comparison between visual fatigue caused by VDT works under LEDs and that under fluorescent lamps

The purpose of this study is to identify the visual effects of the difference of spectral power distribution of luminaires in office space. Subjective experiment was conducted in two experimental chambers with different kind of ceiling luminaires - LEDs and fluorescent lamps. Visual fatigue of the subjects was evaluated by three methods, ART (Accommodation Response Time) and CFF (Critical Fusion of Flicker) as objective test and questionnaires for evaluation of subjective symptoms of fatigue as subjective test. The results showed that there was no significant difference between the variation rate in ART and that in CFF caused by VDT works within one hour under LEDs and those under fluorescent lamps. Also the subjective evaluation on fatigue was not significantly different among different kinds of the light source.