????
They're tired eyes.
In the GQ interview, she admits to needing glasses but not wearing them as much as she should, and that she doesn't wear contacts because she fears putting things in her eyes.
"So I have to wear glasses, and I don't wear contacts, which I probably should, but I have a fear of putting things in my eye, which I'm trying to get over. So I'm constantly either wearing my glasses or my eyes are so strained and red, because they're just constantly not being able to see."
https://www.gq.com/video/watch/10-essentials-10-things-sydney-sweeney-cant-live-without
I am in her boat (I wish) with formerly needing glasses and haveing a violent reaction to putting contacts in.
Eventually got Lasik and now need reading glasses.