Movement phosphenes in optic neuritis: a new clinical sign.

Positive visual phenomena (phosphenes) elicited by eye movements have been described in normal individuals and in myopes with vitreous opacities. In the present paper we describe eye movement-induced phosphenes that appear to be related to optic nerve involvement in patients with optic neuritis and multiple sclerosis. This phenomenon is not associated with vitreous or retinal defects, nor is it similar to phosphenes observed in normal individuals. Instead, it shares many characteristics with the well-known Lhermitte sign and is believed to represent a similar phenomenon.