Pretty fun little invention. Thanx for sharing. One caution for anyone using this, or headlamps, or any other "back-light" that's incorporated some machines: Your eyes/pupils will eventually become focussed on that light. And you'll become blind to everything outside that beam of light. So it's better to let your eyes become adjusted to the moon light, lest you eventually be bumping into bushes, walls, etc.... And only turn on a light when you need to see your screen for some reason . Otherwise I rely on the TID tones when night hunting.
So I wonder if your invention could be modified to have an on/off ?