Purpose of Review: This review covers causes of visual impairment in multiple sclerosis (MS), differential diagnosis, and treatment. Emerging technologies are sometimes used in assessing the visual system and may require a neurologist’s familiarity. The most common causes are emphasized and discussed in detail, including illustrative cases.
Recent Findings: The use of optical coherence tomography as both a clinical and research tool has advanced our understanding of how the afferent visual system is affected by MS.
Summary: Optic neuritis remains one of the most common initial manifestations of MS, although a number of other causes of visual impairment are possible even in the patient with known MS. Some causes of visual impairment are consequences or complications of MS treatment and are particularly important to recognize. Low-contrast letter acuity and optical coherence tomography are techniques or tests emerging from the research arena that may inform care of the patient with MS and are important for the neurologist to be aware of.