TruGlow are Fiber Optics, but also night sights, very bright ones.
My rational for the back and front sights being all green dots (and bright ones!) is simply that it is easier for the eye (read brain) to line up three dots, just a straight line, with the gap on each side of the front sight the same, at speed especially. Than the traditional square in a square, with the tops in a straight line IMHO.
In Florida we get a lot of bright sunlight, turns the Tru Glows into the most bright of the fiber optics, which in turn gives you an ability to look at the target, a natural instinct really, and still have the sights show you their bright dots. To try them is the way to go, borrow a friends pistol, fire two rounds at say a target 7 yards to your front, have a target off to your right, at the same distance, swivel your eyes to target #2, then while focused on the new target, swing the pistol over to it.
The bright green dots appear in your vision, even though you are concentrating on the down zero.
The reason I went to these sights, some three years ago, shooting in a match in Georgia, 4-15PM, the sun slanting across the range, my night sights (Trijicons) vanished! try point shooting at 15 yards!
Pancakes call, First Watch here I come!