Abstract
A clinical case of bilateral descending optic neuritis in a 63-year-old patient is presented. The patient, whose age is beyond the normal limit for this pathology, was previously treated for neuritis of the right eye, which had no effect and led to a complete atrophy of the optic nerve (ON). A timely correct diagnostics of the left eye, which revealed structural disorders of the optic nerve accompanied by inflammatory viral changes of brain tissue, was a key factor in choosing an adequate treatment, which helped retain visual functions. The clinical observation illustrates the polyetiological nature of inflammation of the ON, the viral agent playing a leading role. Importantly, ophthalmic manifestations of the herpesvirus infection may remain the only sign of this pathology for a long time, so the ophthalmologist must always be on the alert regarding the viral genesis of the disease.