Optic Nerve Origin
Optic neuritis often produces phosphenes induced by eye movement or a dark setting. Patients with subacute or long-standing optic neuropathy may experience sound-induced photisms (sensations of color or light induced by a loud noise). These photisms are attributed to discharges from the lateral geniculate nucleus, which is also responsive to sound.
Jacobs L, Karpik A, Bozian D, Gøthgen S. Auditory-visual synesthesia: sound-induced photisms. Arch Neurol. 1981;38(4):211–216.
Excerpted from BCSC 2020-2021 series: Section 5 - Neuro-Ophthalmology. For more information and to purchase the entire series, please visit https://www.aao.org/bcsc.