If you havent seen the movie dont read this, is spoiler alert.
Zod has no purpose on life anymore, he is in a fight to the death, because he cant live anymore, he cant kill Clark also, since he is the only thing that is a part of Krypton, he cant kill him, he does everything so Clark kill him, he cant kill himself because he has a mission, to protect and save Krypton, he cant kill Superman, so he need to push him to the point Superman only has one choice to make, end with Zod life, he have no other desinty or mission, he cant change and get a new life, he has no other option that dying at that point
The heat vision would move if he moves his eyes, still he moves neck so he point Superman what to do, he cant kill himself but he cant keep living, then he force Superman to kill him.
This is pretty normal, is called Suicide by Cop.
Suicide by cop is a suicide method in which a suicidal individual deliberately acts in a threatening way, provoking a lethal response from a law enforcement officer or other legitimately armed individual, such as being shot to death.