采用视觉功效试验,研究隧道暗适应过程中LED光源色温对瞳孔直径、瞳孔面积变化率和反应时间的影响。结果表明:人眼暗适应过程分为初期和中后期两个阶段,前者时长约2s,瞳孔面积变化率频繁超过70%,眨眼频率高达1.7次/s;后者时长约20s，瞳孔面积变化率在±4%,眨眼频率恢复到正常水平。在暗适应初期,LED光源色温越高,人眼瞳孔面积越小,视觉负荷更低,反应更快;而中间色温LED光源更有利于提升暗适应中后期的视觉功效。据此,提出隧道入口段和过渡段的LED光源色温推荐值。

The study aims to investigate the effect of color temperature of tunnel LED light source on pupil diameter, variation ratio of pupil area and reaction time during the dark adaptation through visual performance experiments. Results show that the process of dark adaptation can be divided into two stages, namely, the early stage and the middle-late stage. The early stage lasts about 2s, during which the variation ratio of pupil area exceeds 70% frequently and the blinking frequency rises up to 1.7times/s. The middle-late stage lasts about 20s, during which the variation ratio of pupil area remains in the range of ±4% and blinking frequency returns to normal level. The higher color temperature of LED light source is, the smaller pupil area, lower visual load and faster reaction time is during the early stage. Intermediate color temperature gives rise to a relatively higher visual performance during the middle-late stage. Accordingly, the recommended color temperature of LED light source in threshold zone and transition zone was proposed.