I had a porc that rubbed against glass. His eyes got infected. Luckily my lfs said they'd try and get him better. He died after being in their care for 2 weeks. Ugh, bummer. Good luck with your little guy.
Picture? Could be an infection, I have heard puffers who run up against glass get eye infections. How long have you had him? How big is the tank?
Sorry about the delay I can't figure out how to navigate this site I'm gonna spend some time on it today and try to figure everything out. And for my dogface I did the hypo salanity on him for four weeks he is now fine and back in my DT sorry and thank you