I advised that she get that fish OUT of her discus tank and put it in quarantine, so she did, but then it faded fast and stopped eating. The "string" seemed to go back straight into the fishes head through the back of the eye.
She was treating with prazipro when she decided that the fish was suffering and so sacrificed it (I advised she get some clove oil a long time ago, but she never did, so she put it in the freezer

Anyway, she did an "autopsy" and cut open the eye and looked with a magnifiying glass and the eye was FULL of tiny, little wormlets
that squirmed all around, then died.
She is asking me whether to treat her main tank with her beautiful discus. I have never heard of such a thing as "eye worm" so do not know what to tell her.
Any thoughts, other than YUKKKK?