My English Bulldog’s eye is half-closed for a few days - has anyone seen this before?

Hi everyone! My English Bulldog, Fernando, has had one of his eyes half-closed for a few days now. He doesn’t seem to be in pain, but I’ve noticed he’s blinking more with that eye and has been a bit quieter than usual. I’ll share some photos in the comments for reference.

We’ve already taken him to the vet, and they prescribed an ointment with antibiotics and corticosteroids. However, it doesn’t seem to be working so far, and he’s started trying to scratch his eye.

Has anyone experienced something similar with their dog? Could this mean the treatment isn’t right for him, or does it just take more time to see results? Do you think we should take him back to the vet? Any advice would be super helpful!