AGEING EFFECTS ON DISCOMFORT GLARE SENSATION AND THEIR MECHANISMS (OP13, 94-99)

There are larger individual deviations in sensation of discomfort caused by high luminance glare sources. This is especially true for older observers. It is therefore inappropriate to simply average discomfort glare ratings evaluated by older observers. This study examined individual visual characteristics and conducted glare evaluations of glare sources with different apparent sizes for young and older subjects. Based on the experimental data, this study analyzed the relationship between each of the visual characteristics and Borderline between Comfort and Discomfort (BCD) luminance. The results of the analyses suggested that for the small glare source people who have clearer lenses and larger pupils, and therefore higher retinal illuminance values tend to have lower BCD luminance values. On the other hand, for the larger glare source, people who have larger effective (clear) lens areas seem to have higher BCD luminance values. However, people with very small effective lens areas seem to also have high BCD luminance values. Based on such conflicting experimental results, potential mechanisms of discomfort glare sensation were discussed.