It is hard to see clearly. It didn't affect the actual though right? From what I can see, it doesn't look bad. I would clean it out with just some warm water and make sure it stays clean and that flies don't get into it to lay eggs. Might want to keep him inside until it heals over. If you think you can put some antibiotic cream on it without getting it in the eye, I would do that. Otherwise just clean with the water and keep it clean until healed.