Neither did I (lol)
Vegan sunglasses are eco-friendly ones. In other words, they don't harm any animal or the environment in their process of making. (Google source)
I'd probably prefer the word "eco" or "green", with a focus on the environment in that regard. However, vegans may be drawn to this brand in particular - I do believe it has legs. I suggest "offers accepted", see what comes your way. IMO
For e/c/o s/u/n/g/l/a/s/s/e/s (com) or g/r/e/e/n s/u/n/g/l/a/s/s/e/s (com), I'd appraise Low X,XXX