Benign and malignant neoplasms which arise from or metastasize to the optic or second cranial nerve which extends from the optic disk of the eye and joins the optic chiasm. Clinical features may include visual loss, proptosis, and local pain. The majority of optic nerve tumors or optic gliomas. The disease is Monarch Disease Ontology term MONDO_0002640 (optic nerve neoplasm). Also known as: cranial nerve II neoplasm, cranial nerve II neoplasm (disease), cranial nerve II neoplasms, cranial nerve II tumor, cranial nerve II tumour, neoplasm of cranial nerve II, neoplasm of optic nerve, neoplasm of second cranial nerve.