Optic nerve glioma (or optic glioma), a form of glioma which affects the optic nerve, is often one of the central nervous system manifestations of neurofibromatosis 1.Optic gliomas are usually pilocytic tumors, and can involve the optic nerve or optic chiasm. Optic gliomas are usually associated with neurofibromatosis type 1 in 30% of patients.Optic nerve gliomas have low mortality but extremely high prevalence of vision loss & eye proptosis (exophthalmos) in children. [Source: Wikipedia ]