This was originally going to be like a regular pair of glasses and not a mask, but along the way the direction changed. This is all pretty much free-form crocheting. There isn't any pattern, but I took a lot of photos.
Step 1: Supplies
This instructable does not need very many supplies:
crochet cotton- purple (of course) and also some blue and yellow- alternative yarns would probably work just as well as well-(I used two strands of Craft Thread together for the yellow on this mask as I didn't have any yellow cotton.)
crochet hook/s- started with an 'E' hook, but after finishing the outline, switched to a 'B' hook. The reason being that it was smaller than the 'E' and I had overlooked it earlier when gathering supplies, As is probably evident by now, I'm self taught- was just thinking maybe smaller hook might be better(?)
and an old pair of glasses