Definition: Eigengrau; German; noun
1. 'Dark light' or 'brain grey'; the color seen by the eye in perfect darkness.
Why I love this word:
Eigengrau is a term for that dark grey color your eyes see when you are in a room completely absent of light. I think it's incredibly interesting that in complete darkness, our eyes see not the blackest of blacks, but a grey. A light is always being searched for.
The scientific research behind this word is caused by visual noise in the retinas that produce random events indistinguishable from those triggered by real photons. Because contrast is more important to our eyes than absolute brightness, pure darkness actually looks a smidge lighter than say a really dark night sky against a bright star.
Photograph by Kathrin Koschitzki