Yes, the Nydar sight is pretty cool and has gained a huge reputation through the gaming world for the Call of Duty types.
The Nydar Shotgun Sight gained fame in 1945 for its use on… well, shotguns. This was a remarkably simple contraption, converting Howard’s closed design into a more modern open reflex configuration. Attached to a strip of metal a few inches long, the sight consisted of a front glass roughly an inch and a half in diameter. Back at the rear of the mounting apparatus, a small prism and reticle sat open to the sun. With sufficient ambient light, the reticle would be reflected up onto the forward glass. Unfortunately, this only worked with ambient light that was bright enough - good news in a desert, not so useful in the jungle.
I have a battleworn Galil coming tomorrow and I am going to put one of the earliest LED reflector sights, aka red dot, on it. The sight is an Elbit red dot sight and was used by the Israeli army. Very hard to find, mine came out of Turkey. I'll have to make the mount for it.
Elbit sight on Israeli Galil, circa1998
Working on making the elongated forearm for the browning A5.