If an optic nerve was damaged , what doctor should i seek for eye doctor or a nerve doctor ?

Actually- maybe both: Depends on what you mean when you say "optic nerve damaged" & as importantly what is the resulting disturbance in vision consequent to this damage. In other words, if the nerve is physically damaged such as by trauma then, an ophthalmologist is needed but if a clot causes a stroke in the eye & that's the cause of the damage then, a neurologist is likely better. Or both might be of value depending