He's sick not blind. Check your water parameters, just because you changed the water doesn't mean spit. He may have a swim bladder problem or a parasite, but you won't know till you test your water.
i googled a swim bladder and it does mention about a fish having a curved spine does that mean how he is in the pic i posted above ? how do i treat it ? the site i saw said feed skinned pea's and to lower the water level for him so it easier to get to the top of the surface to eat, all though he is still only eating talapia.... i think is what could have caused it is the powerhead pumping to much air into the water there against him....what do you guys think i should do i havent moved him as of yet i dont wanna stress him out anymore then he already maybe