Betta Fish: How can I help my female betta?

I’ve had this female crown tail betta for about a year now and she had been doing great until recently, she developed some cloudy eyes, and has been rather lethargic and taken to laying at the bottom of the tank, she still swims around when given food and will eat but I’ve tried multiple things to get her back in shape. She was originally in a 20 gallon with some leopard danios and some amano shrimp and ember tetras and she did great with them, and when I noticed she wasn’t doing well I switched her over to a 6.5 gallon to do some treatment on her, the other fish in my 20 gallon are doing fine, I have tried treating her with medicine for the cloudy eyes but it hasn’t seemed to go away and I think she may be blind now but she will still react to light, I’m not sure what to do 🙁