As perplexing as the name may appear, the actual profession is quite cool. In the old days, a Flusssieder was used to make glass. And where would we be without glass? Probably in a dark hole. So, thank you, dear Flusssieder, for making our high-quality panorama peepholes so beautifully transparent. That fits perfectly, because without glass, there would be none of our gorgeous eyewear for you, so in that sense, it's a system-relevant profession, at least to us.