That is really bad. I'm surprised you didn't put it in a quarantine tank. If you had that wouldn't have happened. Put him in QT, add salt, no decor or gravel, heavy filtration, hood. Make sure there are no dangers of injuring his eye. Good luck...
get him out asap.. ask oddball or lupin, i knew this would happen but you said it was just normal pushing around
i think salt and clean water may help, maybe it isnt serious