Effects of light color of illumination and illuminance on visual performance when using matte paper and ink

摘要

This study investigated the effects of light color and illuminance level on the visual performance of subjects aged 23 -69 years when using matte paper and ink. The results of our first study showed the legibility of characters to be significantly better under light with a high color temperature (5800 K - 6700 K) than under low color temperature lighting (2700 K). This result varied slightly with illuminance level: at a low illuminance level (300 lx), the legibility is improved at a high color temperature, but at a high illuminance level (750 lx), the legibility began to fall as the color temperature rises over 6700 K. On the basis of the second study, we examined the decline in visual performance in people aged 50 years and over at high frequencies using our own contrast sensitivity evaluation method. We analyzed how the color of light and illuminance level affect legibility and contrast sensitivity in an older group (50 years and older) and a younger group (under 50 years). This analysis showed that character legibility and contrast sensitivity are higher in the older group at higher color temperatures.