2022 年 45 巻 p. 34-45
This study investigates the effect of blue light emitted by phosphor-converted white light-emitting diodes (LEDs) on people’s eye fatigue. We conducted an experiment in which participants performed a visual task under lighting conditions using a white LED (B-LED) in which blue light excites phosphors and white LEDs (V-LEDs) in which violet light excites two types of phosphors. One of the two V-LEDs had a spectral power distribution mimicking those of the sun (S-LED). During the experiment, we measured participants’ subjective eye fatigue, number of eye blinks, accommodation power and critical flicker frequency. The results of the subjective evaluation suggested that participants’ eye fatigue under the B-LED lighting was worse than under the S-LED or V-LED lighting. The results of the eyeblink and accommodation measurements suggested that participants’ eye fatigue under the B-LED lighting was worse than under the S-LED lighting. In the range of the white LEDs employed in our experiment, we found that participants’ eye fatigue under lighting conditions with a blue-light-excited white LED could be worse than under a violet-light-excited white LED. The results of the objective response measurements suggested that the fatigue of eye muscles is the principal factor causing subjective eye fatigue.
