Correct! The imaging features and the patient’s age strongly suggest a diagnosis of pilocytic astrocytoma (“optic glioma”), a World Health Organization Grade 1 (low malignant potential) lesion limited to the orbital segment of the nerve. He may have neurofibromatosis type 1 (NF 1). There is no evidence that surgery on such a lesion prevents spread to the optic chiasm, hypothalamus, or other optic nerve. Whether to undertake chemotherapy for a lesion confined to one intra-orbital optic nerve is controversial. Many oncologists would defer because anecdotal evidence of benefit is weak and there are no controlled clinical trials. Current regimens, which are vinca alkaloid and platinum-based, are safe but arduous. There is suggestive evidence that checkpoint inhibitors may be more effective. Radiation therapy is not supported by trial evidence and is especially toxic. If serial clinical and imaging examinations were to suggest the development of binocular vision loss or imaging involvement of both optic nerves, the optic chiasm or the hypothalamus, then chemotherapy would be a more viable consideration. Investigation for non-ophthalmic signs of NF 1 is reasonable.