This fabric envelope is a total rip-off of a lovely one that Jessica made me, which I use as a wallet. Since it's not meant to be used as a wallet, and it has no billfold, coin purse, or cardholders, I'm constantly fumbling through it, dropping credit cards, tearing dollar bills, and exclaiming to cashiers about all the Sacagawea dollars I just found in there (!). And I still love it, which means it was a great gift.
I sized this up and elongated it so that it fit my old plastic sunglasses, which I've now broken, and it's slightly too small for the new aviators I just got on sale. (Which will soon also break.) So scale accordingly.