Bubble inside Moors eye?

[milliemara]

I have had my Black Moor for about a year now. About half a year ago one of his eyes became cloudy, we tried treating him for pop eye but it didn't do anything. The eye began to swell up and is much larger than his other one now. The other is also becoming slightly cloudy but the big one seems to have a white bit inside and almost looks like a little bubble inside his eye. He is happy and eats well. He is in a 250l tank with one other telescope.

Does anyone know what I can do or what might be happening?

Thank you!