Just been researching this topic and due to problems my comet is having at present I am wondering how long he can survive without being able to breathe properly.As I am aware a fish needs to take water in through the mouth and pass it out through the gills.So this makes me think the fact his iris's are turning blue that in effect he may well be sustaining brain damage.Anyone else had a fish with breathing problems be interesting to compare notes.

Blue you are right, not really sure what to add to it. How does the fish's gills look? Pale, nice pink/red color or a deep red?

I think you may be better off focusing on his symptoms/water params that he is in,and what you're doing for the fish right now.Can you fill us in on that?

This prob has been ongoing for a while.I have posted his probs on the board over past few weeks.
Regards his gills laurieP they are a bright red.