4 minutes would have been enough for flukes.
I take it the one eye looks different than the other? They do kind of have strange eyes, but if you're seeing a distinct difference from one to the other, there's something going on.
Could be a mechanical injury - a scratch. I'd watch and wait and see if it gets better or worse - but if it worsens don't wait too long to try something else.
My big porcupine had some funk over both eyes a while back, we fed him metronidozole and Focus in his food - took a while, but he got better. He had it really badly too - eyes looked like someone smeared Vaseline over them.
Jenn