I have unfortunately had a blind
betta and it behaves like this:
They swim in a circle at the surface continuously and do not eat anything even if it hits them in the face. She would run right into bloodworms and pellets and just swim right past them. It was really hard to have her and know that she was going to die of starvation. If your betta is indeed blind and not eating at all (you notice I said IF and NOT EATING at ALL) then I would recommend that you think about the possibility of getting some Euthanase from a fish store or from Drsfostersmith.com and gently putting the poor little thing to sleep.
If however the betta is eating and just has "something wrong with their eyes" it could be an eye infection in which case you should get some MaracynII and do water changes to get the water nice and clean and
ammonia free and treat him. His eyes can be saved if you clean his environment and make sure it stays that way and give him medicine if it is an infection like popeye or something.
Now please do as HatchetHaven says and give us MORE INFORMATION. We need to know what the ammonia,
nitrite, and
nitrate levels are in your water,
what temperature you keep him at, what size is your tank, what other fish do you have in with the betta, how long have you had the tank, and is the tank properly filtered and has it gone through the
nitrogen cycle?
How old is the betta and what do you use in the water? Do you dechlorinate your water? How often do you clean your tank and/or change the water and how much do you change at a time? Those are the things we need to know to give you a really good answer to your question.
We will be very happy to help you to the best of our abilities but we need this information so if you could get it back to us or tell us if there is some reason you don't know the information, this would help a lot.
Welcome to Fishlore.com I am sorry about your fish's problem.
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? More info please - that's a tip your going to need here.