OFFICE LIGHTING DESIGN IN CONSIDERATION OF EYE FATIGUE AND TASK PERFORMANCE (OP05, 19-28)

With tuneable LED lighting technology, 12 office lighting conditions was designed with 2 levels of correlated colour temperatures (CCTs) (4000 K, 6000 K), 2 levels of illuminance levels (400 lx, 700 lx) and 3 levels of blue-light peak wavelengths (420 nm, 450 nm, 475 nm). Eye fatigues and task performances of 12 participants was analysed with variables of CCT, illuminance, blue-light peak wavelength, retinal blue-light hazard, and circadian radiometric quantities. The results indicated eye fatigues in 6000 K environments increases higher than 4000 K, and in 700 lx environments increases higher than 400 lx. Task performances in 4000 K environments is better than 6000 K. The 400 lx / 4000 K office lighting is the best one within our test lighting conditions. Retinal blue-light hazard is more useful than circadian radiometric quantities and blue-light peak wavelength in office lighting evaluation. Besides CCT and illuminance, choosing a low retinal blue-light hazard spectrum may be a good strategy.