On any real sunny day, Biden wears sunglasses. If you get him into a room with the lights for camera action...no sunglasses, but he’s got the dark contact-type lenses.
He’s got some eye problem (probably not severe) but you won’t see him walk out into some WH garden in the middle of a July sun situation...without the sunglasses on.

I’ve never seen Trump in sunglasses, now that I think about it. Never.