How Do Pilots Adapt to Night Vision?
As the eye moves from a bright environment to a darker one, the rods of an eye slowly become fully adjusted to the new dim lighting. During and after this period of adjustment, the sensitivity of rods to light is increased dramatically. Due to the length of time necessary to fully adapt to the dimmer environment in the cockpit, night-flying pilots prepare in advance, and avoid exposure to bright light prior to any night flight.
The entire adaptation process is reversed when the pilot enters a well-lit area, or is temporarily exposed to bright light. The reversal/de-sensitization of the human eye takes only a few seconds, which exposes the pilot to temporary blindness upon sudden exposure to bright light sources, and then a much longer period of readjustment to the darker area in the cockpit – this is why cockpit lighting is uses red light, or low-intensity white lights. The specialized lighting allows pilots to first adapt to the dimly-lit cockpit and the night, and then keep their eyes adapted by avoiding bright white lights in the cockpit during flight.
Efficient Night Flying
In order to fly safely at night, a pilot must not only allow the eyes to adapt to the dark atmosphere, prior to flight, but also avoid bright lights during the flight. He should concentrate on objects in his peripheral vision, to get a comprehensive vision of his surroundings, and scan the night sky slowly, avoiding rapid head movements, to directly view indistinct objects.
Although the pilot relies on the instruments in the cockpit, his night eye, steadily focused on the peripheral, and well-adapted to the low levels of light, will always be an added advantage to the modern aircraft equipment for night flying.
Federal Aviation Administration. Pilots Handbook of Aeronautical Knowledge. (2008). Accessed May 17, 2012.
Federal Aviation Administration. Airplane Flying Handbook. (2004). Accessed May 17, 2012.
Oxford Aviation Services. Joint Aviation Authorities Airline Transport Pilot’s License Theoretical Knowledge Manual. (2001). Accessed May 17, 2012.
American Optometric Association. The Eye and Night Vision. Accessed May 17, 2012.
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