Might vary with the make of the sunglasses, but I took an IR photo of a colleague wearing sunglasses, and on the photo the glasses were completely transparent. So the FaceID has a good chance to work with sunglasses.
That’s a bad sign, usually good sunglasses also block IR and UV light, as the eye only closes the iris based on visible light, but can still be damaged by too much exposure in IR or UV bands.
What are some examples of sunglasses that block IR? When I looked around earlier (curious about the same question) it didn't seem to be a standard feature at all.
