BACKGROUND: In multiple sclerosis (MS), even in the absence of a clinical episode of optic neuritis (ON), the optic nerve and retinal nerve fiber layer (RNFL) may be damaged leading to dyschromatopsia. Subclinical dyschromatopsia has been described in MS associated with lower motor and cognitive performances. OBJECTIVES: To set the prevalence of dyschromatopsia in eyes of MS patients without a history of ON, to...