Research on the influence of different environment brightness on human eyes resolution

The minimum resolution is one of the most important characteristics of human vision, during the flight of the aircraft, the pilot uses the head-up display(HUD) to observe and distinguish the information of the external scenery. Analyzing the impact of different transmittance HUD combiner under different environment brightness on the external resolution has important instruction and application value for aviation safety. The experiment uses the UASF1951 target plate and the transmittance of HUD combiners under two different environmental brightness. Record the minimum resolution angle and the difference between the two conditions. The result shows that, under the same brightness, the lower the contrast, the weaker the human eye can recognize; the minimum resolvability of the human eye is affected by contrast: when the brightness is lower, the lower the brightness, the higher the minimum contrast requirement for human eye to recognize objects. When the brightness is higher, the minimum contrast requirement for human eye to recognize objects does not change much with brightness, and after the brightness is increased to a certain range, the minimum contrast required by the human eye to recognize the object is almost unchanged. It can be seen that the resolution of the human eye is simultaneously affected by environmental brightness and contrast, and the experimental results basically conform to the Adrian's Visual Acuity Model.