Night vision and Altitude

[Brandon_L]

I'm looking for info. pertaining to night vision and the changes that occur involving vision at altitude. Especially as it applies to the pilot.

[RitaMimiKing]

a few months ago I was visiting a friend at her cabin in Montana. It was at a high altitude. I had no problems adjusting to the altitude, however one morning upon awakening I had lost my color vision. I could only see in black and white and shades of gray. This last about 15 to 20 minutes. When I moved my hands, it was as though a camer lens was taking rapid shots of my hands moving. Very odd, then it went await and I felt as if I literaly stepped back into the colored world.

[PaulMD]

Hi there.

Broadly speaking, objects appear smaller at night due to the loss of distinct edges.  Color discrimination is also impaired since color is a function of adequate light that hits the eye.  High altitude, if you are out in the open may affect the eye sight by causing some distortion (since air is thinner in increased altitude).  Objects may also seem smaller or there can be problems in depth perception.  If you are in a pressurized cockpit, there should not be any significant effect of altitude on the eyes.

Regards.