照明光源的频闪对视功能的影响

The effect of illuminantion light source's frequency flicker on vision function

目的 探讨频闪与视疲劳的关系，寻找减轻船员视疲劳的方法。方法 观察３０名被试者在两种不同的照明电光源下，阅读６号字体的文章６０ｍｉｎ前后的常规视力、对比视力（对比度为９２％，５２％，３０％，１１％）、对比敏感度（空间频率为１．２，２．４，４．８，９．６，２０，３６周／度）。结果 被试者在视觉负荷量相同的情况下，他们的常规视力、对比视力、空间频率在高频处的对比敏感度均下降，下降幅度在使用有频闪交流荧光灯时比使用无频闪直流荧光灯时大。右眼常规视力下降相差０．０４，左眼常规视力下降相差０．０４（均Ｐ＜０．０１）。右眼对比视力在相应对比度处下降分别为０．０６，０．０４，０．０４，０．０７（Ｐ值分别为＜０．０１，＜０．０５，＞０．０５，＜０．０１），左眼对比视力下降分别为０．０４，０．０５，０．０８，０．０７（Ｐ值均＜０．０１）。当空间频率在２０ｃｐｄ时，对比敏感度值下降１７．３（Ｐ＜０．０１），在３８ｃｐｄ时下降６．１９（Ｐ＜０．０１），均有统计学意义。结论 频闪对人的视功能影响较大，使用无频闪照明电光源是一项改良船舶舱室光环境的有效措施。

Objective To explore the relationship between frequency flicker of light and as- thenopia, so as to find a method of alleviating asthenopia in seamen. Methods Under the illuminant conditions of two different light sources, 30 subjects with normal eyes were told to read some articles printed with Chinese characters No. 6 for 60 min. Then their Snellen acuity, visual acuity at 4 contrast levels (92%, 52%, 30%, 11% ) and contrast sensitivity at 7 spatial frequencies (cycle degree: 1. 2, 2. 4, 4.8,9.6,20,36) before and after the readings were measured. Results There were significant differ- ences in the changes of above visual indexes under the two illuminant conditions. The decreases of above indexes values were bigger using A. C. fluorescence lamp with frequency flicker than D. C. lamp with- out frequency flicker. The right eye's snellen acuity decreased 0.04 and the left eye's snellen acuity also decreased0.04 (P<0.01);the right eye's contrast visual acuity decreased 0.06, 0.04, 0.04 and 0.07 re- spectively (P values were <0.01, <0.05, >0.05, <0.01) and the left eye's contrast visual acuity de- creased 0.04,0.05,0.08 and 0.07 respectively(P values were all <0.01); the contrast sensitivity at 20 cpd decreased 17. 3(P value was <0.01 ) and at 38 cpd decreased 6.19(P value was <0.05). All of them had statistical significances. Conclusions Frequency flicker of light has prominent influence on human vision function. Therefore, the use of light source with no frequency flicker is an effective way to improve the lighting environment in ship cabin so as to alleviate asthenopia.