Dovii RED EYE

[OPEN WATER PREDATOR]

I noticed this yesterday. My large male dovii's right eye is completely red. He appears to still see just fine with it (still attacking me through the glass when I'm on that side) but it's really freaky. Has anyone ever seen this before? Any clue what the problem is? I'm guessing it's a burst 'blood' vessel? ...at least that's what it looks like to me. Can I expect this to mend?