Sick betta -- ring around eye

Question
Good morning,
My question is about my betta fish, Boris.  I recently moved to another state and left the fish at my parents' house.  They mentioned about a week before that he had a white ring around his eye, and when they brought him down three days ago and I noticed that the white ring is very pronounced and the eye is also swollen with a small indent in the center.  The ring goes almost completely around the eye and is raised up and sort of cotton-y looking, which made me think it might be a fungus.  He's in a 2.5 gallon tank, I've been changing and testing the water every other day to make sure it stays very clean, and treating him with the recommended dose of Jungle brand Fungus Clear but with little improvement.  If anything I think it might be getting worse and even spreading to the other eye.  Other than this swollen eye he has been acting normal other than that he wont flare at his own reflection.  He eats like a pig when I feed him every morning, making bubble nests like mad, and swims all around.  What do you think this could be and what should I do about it?  This fish means a lot to me and I feel responsible for him, thank you for your answer!

M.

Answer
Hello,
This could be caused by many things.  When this happens to a fish, it is called "Popeye."  When fish have Popeye, it usually covers another disease, so watch carefully.  Your water should always be free of ammonia, and nitrates.   It could be a bacterial infection, feeding him medicated food for bacterial diseases should help.  It could be viral, it could be eye flukes.  There are so many possible causes that I would recommend "Kamamycin" or "Tetracycline," or Maracyn 2.  
Feed him 2-3 small meals a day.  One big meal is not good for Bettas as their tummy is the size of his eye, so small meals rather than big ones.  Example:  2 pellets to one meal.
Always keep his water clean, and changes every week.  His water temperature should be around 80 degrees.  He is a tropical fish, and under this temperature he gets cold, and therefore gets sick.  When raising temperatures for bettas, always do this slowly, one degree every 2 days, as raising the temperature quickly could kill your betta.
I hope your fish recovers, and that this will help. If you have any other question, do not hesitate to ask.
Lynda