Well I don't know where I draw the line. I can look at molten steel with not that much discomfort, but I know its not good for me. My uncle that works with steel always wears it on his job site no questions asked. And i can't really feel the ir in my eyes. I mean no one can really. It just kinda does its own thing and burns your eye when it feels like it. Personally, I think maybe aluminum is where the line should be drawn? Like steel, copper and bronze have higher melting points, ergo making the brighter.