Looks like the eye is damaged- the best thing you can do is to keep the water clean and his stress level low.
Melafix may help healing, and Pimafix isn't a bad idea. If you see a fungus develop, then you should look at an anti-fungal med.
Melafix may help healing, and Pimafix isn't a bad idea. If you see a fungus develop, then you should look at an anti-fungal med.