Well AUM does has explained it, but they have used a fairly outdated technique... They've simply put a sprite in front of the camera, and turn it on and off... I think you should ask ello about this, he's made some demo's with really amazing effects, by using this technique on models I believe... Don't expect to find a shader example in the older AUM's though..... It probably would be possible to use a shader effect on a model or sprite in front of the camera which produces a nice nightvision effect, but since I haven't got A6 com yet, I can't tell you how you should do it (yet
)....
Cheers