I am glad he is not blind and hopefully not sick ... Because if he didn't have any problem before and now all of a sudden he can't find food and swimming erratically something can bother him. So make sure there is not new symptoms develop:)
I also will keep this link if i ever see that someone have blind betta. Thank you every one for advice, it so amazing that people really care on this forum about those little cute bettas. This thread is so helpful for the people who might experience the same problem with their betta.