Optimize Screen CCTs in 3000K and 5000K Ambient CCTs

Researchers sought to optimize the CCT of lighting and display products for visual and non-visual benefits. However, as actual indoor CCT is determined by multiple light sources, CCT optimization of a single light source is inadequate to obtain proper indoor CCT. To figure out optimized screen CCT for different ambient CCTs, we performed human factor experiments on participants who executed screen-watching task, and compared variations of modulation transfer function (MTF), fundus vascular density (FVD), and visual comfort level (VICO) in different screen CCTs with 3000K and 5000K ambient CCT respectively. We found that values of ΔMTF, ΔFVD and VICO were similar in 5000K yet distinct in 3000K ambient CCT. Our finding suggests that the average level of automatic screen CCT of most smartphones in the market is appropriate in 5000K ambient CCT, while the level in 3000K ambient CCT needs to be reduced for optimization.