Platty pop eye

[Mishellfish]

Hi, I have a make platty, he had quite a fat tummy when I got him but it soon went back down to normal when he was in my tank.
Yesterday I think I fed the fish a bit too much, some of the rainbow fish and especially the platty were looking a bit too fat.

This morning all were back to normal apart from my platty has one badly swollen eye. It is the eye ball it’s self not just the surface.
He has never had any trouble swimming, the water is good.

Please can anyone give any advice?

[TropicalFishForums]

[Mishellfish]

Just to add that he has dark pigmented black eyes as well which make him look a bit panda like