How do you know if a fish is blind?

I ask this because i fed my new boy just now and he just carried on swimming madly around the tank, happy like he has been. I wiggled my finger in the weater as a sign for its feeding time and when i fed him he didnt see the flake, not even when he swam past it. Could he be blind? I tried a few times and its like he couldnt see the food?

Mine do this occasionally hon, sometimes they are in different moods. Unsure on the proper ways of telling blind fish, but he is still setlling so give him time x

ok will do (: he may just want to explore and egnore the food lol?

Yeah hon me thinks so. Give him time and over the next couple of days (weeks!) get used to his behaviour as he gets used to his surroundings and you x

Mine do this when they are new and don't know what happens at feeding time. All the boys I've had for a while come up and say hello when I come to the tank and they all know that if I put my hands in/near the tank, food is likely to be on it's way. The new ones just need to get used to this. Rei and Orion always used to ignore food and now they come up and beg for it. It's super cute.

Ah ok! Well thats a weight lifted lol :D Will try feed again later, thanks

perhaps if it persists you could try feeding him pellets? I know loads of lfs's use flake but bettas actually prefer pellets and they are generally a better source of nutrients keeping your betta healthier

My Deakin does this all the time, a pellet passes right over his nose and he doesn't seem to see it but when it comes round in the flow he swims for it so I don't think it's eye sight [You must be registered and logged in to see this image.] Perhaps they get too excited they just miss it [You must be registered and logged in to see this image.]

I have a girl with a bad eye, and it's very obvious that one side is completely blind, I think you would instantly be able to identify differences in behavior that would suggest acute blindness--however, it seems that fish and other aquatic animals are much more drawn to movement, as Ashton's post suggests. Perhaps try less of a poke and more of a wiggle. Also, smell plays a fairly significant role in a betta's attraction to food. If you pre-soak the flakes/pellets in a bit of tank water so they get good and soggy before you feed your fish, the odor will diffuse more quickly and they will be healthier and more appetizing to your fish. It's also possible that if you have some excessive lighting, it could cause some vision problems.