Study of visual acuity and reaction time at different contrast levels under dark environment in military helicopter flight cadets
10.3760/cma.j.issn.1007-6239.2015.03.009
- VernacularTitle:暗环境下军事直升机飞行学员不同对比度视力和反应时间的研究
- Author:
Haixia RU
1
;
Dongchen YIN
;
Ruihua ZHAO
;
Qian CHEN
;
Wei XU
;
Rong ZHAO
Author Information
1. 空军总医院眼科,北京,100142
- Publication Type:Journal Article
- Keywords:
Vision tests;
Reaction time;
Contrast sensitivity;
Flight cadets;
Helicopter;
Dark background
- From:
Chinese Journal of Aerospace Medicine
2015;26(3):198-202
- CountryChina
- Language:Chinese
-
Abstract:
Objective To investigate the variation of visual acuity (VA) and reaction time at different contrast levels under dark environment in military helicopter flight cadets.Methods Fortytwo military helicopter flight cadets (84 eyes) with normal VA were enrolled.LogMAR VA and reaction time were measured at 4 contrast levels (100％,25％,10％,and 5％) under dark environment by multi-functional visual acuity tester (MFVA-100).ANOVA,paired-simples t-test,and linear regression analysis were used by SPSS 16.0 to analyze the data.Results LogMAR average VA of right eye at 100％,25 ％,10 ％,and 5 ％ contrast levels was 0.007± 0.141,0.256 ± 0.162,0.453±0.182 and 0.711 ±0.232 respectively.LogMAR average VA of left eye at 100％,25％,10％,and 5％ contrast levels was-0.017±0.137,0.266±0.144,0.434±0.145 and 0.697±0.176 respectively.VA decreased gradually with the decrease of contrast level.VA was no statistically significance between right and left eyes at same contrast level (P＞0.05).VA at 100％ contrast showed positive linear correlation to the visual acuity at 25％,10％,5％ contrasts respectively (r =0.432-0.626,P＜ 0.05).Reaction time slightly increased with the decrease of contrast level.Reaction time was no statistically significance between right and left eye at 100％ and 25％ contrast levels (P＞0.05),but the reaction time of right eye was longer than that of left eye at 10％ and 5％ contrast levels (t =2.355,2.055,P＜0.05).Conclusions The study result objectively indicates the situation of contrast visual acuity and reaction time in military helicopter flight cadets and would provide reference to the assessment of visual function in the selection of aviation cadets and the examination of pilots.
