Perhaps because of its various attractions, night flying presents its own set of challenges. Let the sun go down, and all kinds of aviation-related mischief can ensue. The basic problem, of course, is humans are not well-adapted to seeing and doing complex things in low-visibility conditions. So, we have to compensate.
Because of the human eye’s limitations, the FAA and other authorities include several recommendations designed to minimize their impact. For example, and according to the American Optometric Association, “At night, if runway lights viewed from an approaching aircraft are displaced laterally, the pilot may have the impression that the runway is closer than it really is, because it appears wider. This false perception may result in an early flare and a tendency to land short. Also, the intensity of runway lights may appear to vary, depending on their color and the adaptation states of the eyes. These differences in the brightness of runway lights may lead to false perceptions regarding altitude.”
