Note the glow of my front sight, bottom picture - it does that even in daylight when shooting in the bush - it doesn't need to be back lit when on a dark object, like the hide of a deer, elk, moose or bear, black or brown.
The reason it glows softly, is it has about a 45 degree slope to it for it's 1/16" diameter, maybe a bit larger than that. At 1/8", it would be like a beacon or a 'dangerous game night sight'. The 45 degree surfce is lightly polished. It takes a swipe of felt pen to darken it, or sight spray and a mere wipe with your thumb makes it bright again. The backof the sight is angled, but the corners are sharp - this helps prevent windage problems with a lot of beads or rounded blades. Light coming in from the side, makes you miss. This doesn't happen with the flat, sharp edged, angled, shiny sight.
We also do this with our blades - back corner is angled 45 degrees for about 1/16" or even 1/18th inch, and polished - maybe 400grit. It collects minor light in the bush and shows beautifully on animals and dark targets, yet on light ones, still shows as a blade or bead- darkened or not - whichever the light conditions demand.
