I wear transition lenses and they do darken somewhat while I'm welding or working with a welder. They respond to ultraviolet light, so the fact that they do darken somewhat indicates there is a limited amount of ultraviolet light in the area. I suspect the UV is reflected off the surfaces of the work, wall, ceiling, etc.
They do not darken sufficiently to protect your eyes while using a cutting torch, but they are most likely better than nothing. Now that I've said it, I have never qualified a brazer that wore protective goggles while brazing. It was one of those things that was taught as soon I learned to braze in high school, "always wear the proper filter lens for the work being done."
I often wonder how many of these people will develop cataracts at an early age because they didn't protect their eyes from the harmful rays and heat while they braze or use the cutting torch.
Best regards - Al
It is surely something to be concerned about. I am glad that I took care of my eyes, sometimes as a result of the prodding of a safety representitive, as they are one of my most valuable assets being an inspector.
Jenn, the " not supposed to wear contacts while welding" is an urban legend. It's totally fine to wear them while welding.
That's good, because, I can't see as well with the glasses as I can with the contacts for some reason.
I learned to braze from My Grandpop, he was a machinist, and pretty darn good at brazing/braze welding [He didn't gas or electric weld at all]. There is a color change in the material that You can only see with the brazing goggles on that tells You when to add the filler. I have brazed with and without the goggles, but that color change helps make a neet job of it.