I found these sunglass shades that clips on to the bill brim of my baseball cap. I personally use this to free my ears for mask wearing. I find these unusual sunglasses are useful. I can adjust it a few notches forward or backward. And I can flip it up when walking indoor.
Clip on cap Sunglasses (affiliate): amzn.to/3ngWqnn
I've never seen these kind of sunglasses anywhere in the stores. Makes me wonder why didn't somebody think of this before.