Gas bubble inside eye of red devil

[Hipporhyn]

Hi Monsterfish keepers. Yesterday my red devil (Bruce) developed a gas bubble inside his eye. It is not swollen. He is otherwise is good health. Water conditions are excellent. Has anyone seen thus before? Any idea what I should (or can) of about it.

 

[Brettnewell4454]

My ob peacock has a spot like that on his eye. He got it years ago when he took over the tank as top dog. I'm pretty sure mine Is blind in that eye. Just monitor it, and maybe add some salt.