Evolutionists try to claim that any change in information is an example of evolving. That’s wrong because evolution is supposed to be a change for the better, not for the worst. The fish evolving, in this instance, would have been the ability to see in the dark. By evolving infrared vision like snakes have. Are evolving extra feelers like whiskers, so they can feel by touch which is a form of actually seeing.
But instead the fish just went blind.
Going blind is not adapting to the environment to survive. Going blind is letting the environment control if you lose or gain something. So no new information was written to do this, information instead was lost. So no evolution took place.