Assessing retinal hazardous effects from phosphor converted Light Emitting Diode (LED) lighting with different Correlated Color Temperature (CCT)

Due to the rapid growth in the use of blue-light-based electrical panels and much brighter lighting environments, the socioeconomic impact by retinal light injury is critical. Understanding the material property and mechanisms underlying this hazard is important for both effective and user-friendly product development. The InGaN based blue LED has been applied to excite the yellow phosphor (Y₃Al₅O₁₂:Ce³⁺) for white light generation. In this study, custom-made phosphor-converted white light emitting diode (pc-WLED) with correlated color temperature (CCT) ranging from 2700K to 6500K were used for exposure treatments to assess the potential retinal injury. We examined LED induced retinal neuronal cell damage in a rat model through functional and histopathological measurements. Electroretinography (ERG), hematoxylin and eosin (H&E) staining, and transmission electron microscopy (TEM) were used for pathological examinations. The experimental results indicate that blue-rich-LED light could induce more photochemical injury to the retina after the exposure. The results of this study suggest that retinal injury is mainly induced by photosensitizer- and photopigment-mediated oxidative stress with color temperature dependent effect, and users should be more aware of this effect before switching to LED lamps for domestic lighting.