I really think if you go to your welding supplier you will find that the glass inserts used in welding helmets are very inexpensive. Most welding suppliers also have a selection of dark polycarbonate "sun glass" style safety glasses that welders and people that work near them use when not directly performing welding operations.
I say this as long time member of ABANA (Artist-Blacksmith's Association of North America) One of the key safety issues for long term Forge/Kiln/Glass workers is the exposure to, not only ultraviolet radiation. but also long wave infrared radiation. The damage that the eyes receive from high temperature exposure is cumulative.
I hope you have a lovely holiday and a safe New Year.