One of my male Mollies had popeye. It can be due to less than ideal water quality but mine got it from bumping into something in the tank. His eye was very swollen and fluffy. I used Interpet No.9 and it worked very well. I had never used medication before (or since) but I found the instructions very easy to follow. The fish is ok now but his eye never went back 100%. Hope this helps and your fish is ok. I got the medication from lfs. P.S. Don't mean to imply anything about your water quality! That's just what it says in the medication leaflet.