I just received results from an mri and was wondering about what the heterogeneous abnormal term means: "severe atrophy of the right optic nerve within its cisternal and intraocular divisions, with heterogeneous abnormal signal throughout the nerve."

A person with this result likely has blindness in one eye (monocular blindness) due to optic neuritis which is a common finding in multiple sclerosis.

This describes prior and now chronic damage of the right optic nerve. This will affect right visual acuity. Many causes but the severity might be consistent with Neuromyelitis Optica. Suggest search to confirm cause