When I am on a cycletrack that I know at night, I often switch my headlight off, let my eyes get used to the dark, and then cycle the path by sight. 'Tis amazing how much more you often see than if you are relying on a beam of light.
Digressing slightly...
On a dig some years back, camped in the middle of nowhere, the pub was a couple of miles away along an unlit lane. One of my mates, Trev, told me he was doing the walk without a torch to develop his night vision, He said he found that his vision was a bit like what you see through night vision cameras - a bit grainy with flecks of light. Something to do with the fact that the rod cells in the eye are more widely spaced than the cones that detect colour.
Anyway, one evening I joined the pub goers, and among them was a young lad who had a tendency to impose himself on groups. On the way back, Trev and I were testing our night vision, and Trev said "There, are you getting the flecky effect?"
The young lad piped up "What's the Flecky effect?" and on the spot, Trev and I made up a German 19thC scientist, Gustav Flecke, who experimented on his own night vision by walking in the Black Forest at night without a lantern. By the time we were back at camp. we'd given hi whole biography. He'd married a woman named Magdeburg, whose family disapproved, but then they were very rich, having made their fortune in Viennese wig-curlers.
The problem was that the lad fell for it hook line and sinker. When we got back, he thanked us for telling him all about it. By then, it was too late to explain. As far as I know, he believes it to this day...
So, a confession of sorts...
[/quote]
and I was over taken by a jogger on a steep hill 
