Yes, Neurologists. Neurologists specialize in disorders of the brain and nerves, including the cranial nerves. A sudden problem with a cranial nerve should be evaluated urgently in the er. For a chronic problem, ask your primary care physician for a referral to a neurologist.
Cranial nerves. Dysfunction of cranial nerves is uncommon, but always requires a work up. The third nerve which supplies eye muscles and pupils most commonly is affected by vascular events in the brain and is frequently related to diabetes. Less common it is due to tumors and trauma. A neuro-ophthalmologist can sort this out for you and recommend treatment if possible.