a blurring of vision, as if by a red mist, caused by the forcing of blood into the head during feet-first acceleration, as in flying
See redout in American Heritage Dictionary 4
(rĕdˈoutˌ)
noun
A sudden reddening of the visual field accompanied by severe headache and caused by engorgement of the blood vessels of the head when a person is subjected to a negative force of gravity, as in stunt flying.