Mann J, Hovis J
School of Optometry, University of Waterloo, Ontario, Canada.
Aviat Space Environ Med. 1996 Aug;67(8):739-45.
Most of the research on near visual acuity and pilot performance has concentrated on the effect optical blur has on the readability of navigation charts. In order to determine how reduced visual acuity could affect other aspects of pilot performance, we investigated the effects of optical blur on simulated instrument-flight-rules (IFR) approaches.
Simulated IFR approaches were performed under 4 different levels of optical blur by 15 instrument rated pilots. The simulator resembled a single engine aircraft with basic IFR instrumentation. Light levels were selected to represent both day and night time flight conditions.
The majority of the subjects maintained adequate control of the aircraft to the decision height under all levels of optical blur. The root-mean-squared values for the localizer position during the inbound phase degraded significantly at the worst acuity levels of 0.78 and 0.90 logMAR under daytime conditions. However, RMS values under nighttime conditions were not significantly affected by optical blur. The major effect of reduced near acuity on IFR approaches was the inability to resolve the detail on the approach plates and radios.
The major decrement in performance as a result of reduced near acuity is the inability to read the approach charts and radio settings. If this information is provided to the pilots, then they should be able to continue successfully the IFR approach to the decision height.
大多数关于近视力与飞行员表现的研究都集中在光学模糊对导航图可读性的影响上。为了确定视力下降如何影响飞行员表现的其他方面，我们研究了光学模糊对模拟仪表飞行规则（IFR）进近的影响。
15名拥有仪表等级的飞行员在4种不同程度的光学模糊条件下进行模拟IFR进近。模拟器类似一架配备基本IFR仪表的单引擎飞机。选择光照水平以代表白天和夜间飞行条件。
在所有光学模糊水平下，大多数受试者都能将飞机控制到决断高度。在白天条件下，当视力最差为0.78和0.90 logMAR时，进近阶段航向道位置的均方根值显著下降。然而，夜间条件下的均方根值并未受到光学模糊的显著影响。近视力下降对IFR进近的主要影响是无法看清进近图和无线电设备上的细节。
近视力下降导致的主要性能下降是无法读取进近图和无线电设置。如果将此信息提供给飞行员，那么他们应该能够成功继续IFR进近至决断高度。
