Visual and non-visual effects of the phosphor-free white LED lamps rich in the 535–589-nm yellow-green light

Abstract

Despite an increasing number of researches focused on the photo-biological effects of lighting on visual and non-visual health, insights into the phosphor-free white LED lamps with different spectral power distributions remain unclear. In this study, human factors experiments were conducted with 30 participants. Variations in ocular physiological parameters and melatonin circadian rhythms were assessed for participants in an ordinary lamp, a full-spectrum lamp, and four phosphor-free white LED lamps rich in the 535–589 nm yellow-green light. It was observed that ocular functions exhibited significantly higher improvements under the four phosphor-free LED lamps compared to the ordinary and full-spectrum lamps, indicating the advantageous effects of phosphor-free lamps rich in the 535–589 nm yellow-green light on both visual and non-visual health.