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

Abstract

AbstractLight‐emitting diode (LED) light source has high intensity emission of blue components absent in the daylight spectra and regulates human physiology and behavior. The aim of this study was to explore the effects of LED tunable white light with different blue‐component intensities on visual fatigue based on human eye photoreceptors. The short (S)‐cone and melanopsin illuminance were about 212% and 82% higher for blue‐enriched white light than blue‐less white light, respectively. The photopic illuminance was same for these two lights. The results revealed that blue‐enriched LED tunable white light with higher illuminance of S cones had a significant effect on visual fatigue. Participants experienced more eye discomfort under blue‐enriched white light accompanied with decreased vision function and changes in the autonomic nervous system. Visual acuity and tear film stability declined, and heart rhythm changed more significantly under blue‐enriched white light than blue‐less white light. While memory performance did not decline with more severe visual fatigue, improved memory performance under blue‐enriched white light may be due to enhanced alertness or arousal associated with high melanopsin illuminance. Our results suggest that blue‐enriched white light with higher illuminance of S cones and melanopsin has beneficial effects on cognitive performance, but it can induce relatively more visual fatigue.