Goldfish are much cleverer than you think they are, but unfortunately much stupider than they think they are. Poor Poggle my Bubble Eye got one of his eye sacs stuck in the prefilter last night so I literally had to cut it off him (prefilter not eye sac!!) looking very poorly.
Oops - poor Poggle! Mela/pimafix plan sounds good to be on the safe side, as long as the water's clean he should heal up ok Probably just feeling a bit sorry for himself, a nice bloodworm usually cheers them up