Hi Kjeanes.
do you have a pic?
Popeye can be caused by a bacterial infection as well as an abrasion from something in the tank.
I believe it can be hard to distingush exactly what caused it.
Good water quality is a must.
Personally, I don't think i would remove the fish as it might cause more stress and damage to the eyes.
You can try enriching his food with some vitamins.
you can also do a search for epson salts. I have never used it or had any expereince with it, some people like it some don't.