不同机种飞行员暗环境下对比度视力和反应时间

Vision and Reaction Time of Different Aircraft Pilots at Different Contrast Levels in Dark Environment

目的观察不同机种飞行员在暗环境中不同对比度下的视力和反应时间。方法测量不同机型的75名男性飞行员在暗环境下的对比度视力和反应时间，年龄22-38（26．44±2．84）岁。按机种不同分为直升机组（54人108眼）、运输机组（5人10眼）、歼击机组（16人32眼）。先测量三组正常环境下的裸眼视力，再测量三组飞行员在暗环境正常背景下100％、25％、10Yoo和5％对比度下的视力和反应时间，先后测量右眼和左眼。比较各组不同对比度下的视力和裸眼视力的差别、暗环境各对比度下的视力和反应时间的差别。结果三组飞行员正常环境下的裸眼视力差异无统计学意义（P〉0．1）。直升机组100％对比度视力较裸眼视力好，差异有统计学意义（P〈0．05），运输机组和歼击机组100％对比度视力与裸眼视力比较差异无统计学意义（P〉0．05），其他对比度下各组的对比度视力均较正常环境下的裸眼视力差，差异有统计学意义（P〈0．05）。随对比度下降，各组对比度视力下降，反应时间延长。在各种对比度下，直升机组对比度视力较歼击机组好，差异有统计学意义（P〈0．05）；运输机组与其他两组之间差异无统计学意义（P〉0．05）；100％、25％和10％三个对比度下直升机组反应时间较歼击机组快，差异有统计学意义（P〈0．05），运输机组和其他两组反应时间比较差异无统计学意义；在5％对比度下三组之间差异无统计学意义（P〉0．05）。结论不同机型的飞行员，虽然裸眼视力无明显差异，但在暗环境正常背景不同对比度下的视力和反应时间存在差异，直升机组较歼击机组对比度视力好，反应速度快。飞行员低对比度视力检查结果可为建立不同对比度下的视力正常值标准提供参考。

Objective To investigate the vision and reaction time of different aircraft pilots at different contrast lev- els in dark environment. Methods Vision and reaction time of 75 male pilots aged 22-38 （26. 44± 2. 84） years at different contrast levels in dark environment were examined. They were divided into helicopter group with 54 cases （108 eyes）, transport unit group with 5 cases （10 eyes） and fighter group with 16 cases （32 eyes） according to the types of the air- craft. Uncorrected visual acuity （UCVA） in the normal environment was tested at first. Then the vision and reaction time at 4 contrast levels in the normal background in dark environment was tested. The UCVA, contrast visual acuity and reac- tion time were compared. Results UCVA was no：t significantly different among three groups under normal circumstances. In helicopter group, 100% contrast vision acuity was better than UCVA （P〈0. 05）. In transport units and fighter group, there was no significant difference in 100% contrast vision acuity and UCVA. The vision acuity was poorer than UCVA in the other 3 contrast levels in every group. With the decrease in contrast, contrast vision acuity was decreased and the reac- tion time was prolonged in all the group. The contrast vision acuity was better in the helicopter group than that in the fighter group, and there was no significant difference between the transport aircraft and other two groups. The reaction time was shorter in the helicopter group than that in the fighter group in the 100%, 25% and 10% contrast, and there was no significant difference between the transport aircraft and other two groups. There was no significant difference a- mong three groups in the 5% contrast. Conclusion The UCVA is not significantly different among three groups under normal circumstances. The contrast vision acuity is better and the reaction time is shorter in the helicopter group than the fighter group under dark environment. The results of low contrast vision acuity of the pilots provide a consult for the es- tablishment of the standard vision in different contrast levels.