alt Hacker NewsVision is absolutely a superpower if everyone else is blind. Just think how far you can shoot something with a rifle and scope. Guns are useless to blind people. A person who can see has an enormous advantage over a blind person in a fight. Try to imagine a military where everyone is blind fighting against another where everyone can see.
In a blind culture there probably are no guns at all - so your hypothetical sighted-person-amongst-the-blind would need to be able to make his own.
Then again, just throwing rocks might be pretty effective.