I think the glow of the goggles was for you, the player of Sam, to know just where he was in those really dark spots of the game. There really is no visible light or even any glow on the real things. The center node is where the IR light is emitted, much like a flashlight, so Sam can 'see' with them. These are essentually passive, and require the 3rd node to actively emit an IR light source. I am totally interested in these goggles as well. And, for M2 is just fine! I actually prefer M2 to M3 anyway.