So my black skirt tetra lost an eye and now he is agresive?

Jeremy Kenny has something there. If all you're seeing is chasing and there's no radically torn fins or wounds he'll be fine. He's having to accommodate for the lost eye. Watch him closely and watch for infection in the eye and if he starts injuring your other tetra's separate him and do a little aquarium salt or "Stresscoat" for stress and see if that helps. Make him as comfortable as possible There's no reason he shouldn't be able to live a healthy happy life (after the initial shock of the injury at least) as they're shoaling and follow the group most of the time.