to give you an idea of how bad a welder can burn you, my eyes where black until i was 17 and i got flash berned so bad the pigmentation in my eye bleached, my eyes are now green, light green
also went blind for three weeks when this happened. no joke man, as a former professional welder, i recomend covering all skin and your face
I have permant bloodshot eyes from flash, I didn't go blind but had patches over my eyes for 2 weeks just loaded with some Vaseline type gel to keep them from burning. Long story but I'll make it short don't open a door when someone is welding on the other side, or he shouldn't have been welding behind a closed door that someone may open to come inside.