A simplified approach to evaluation retinal blue light hazard using the correlated color temperature of LED light sources

Visible light of short wavelength (blue light) can cause a damage to the retina cells, called blue light hazard. In order to protect the retina, permissible exposure limits have been determined by ICNIRP and other health and safety agencies, which includes complex physical concepts and their evaluation requires light measuring instruments equipped with blue light hazard function filter which is not available at the moment in developing countries. This study aims to assess retinal blue light hazard using the correlated color temperature of LED light sources.

In this study, a new method was proposed for evaluating the retinal blue light hazard using only the correlated color temperature of LED light sources for which concern on blue light hazard has currently been reinforced. In the proposed method, the radiometric quantity (blue light effective radiance) in W.m-2.sr-1 was converted to the corresponding photometric quantity (blue light effective luminance) in lm.m-2.sr-1, and then a computer code was developed for calculations.

The estimated permissible exposure times applying the new photometry approach was highly reliable and supported by the literature. The proposed method is particularly useful because it eliminates the need to utilize any light measuring device.

The new approach makes the concept of blue light hazard very simple and understandable for all specialists dealing with optical radiation safety.