This document discusses visual field changes in patients with multiple sclerosis (MS). MS is a chronic neurodegenerative disease that attacks the central nervous system and has an autoimmune nature. While symptoms affecting the anterior visual pathway like optic neuritis are not universal in MS patients, subclinical visual involvement is common. The document finds that three-quarters of MS patients without a history of visual symptoms had abnormal visual fields, with the most common defect being an arcuate scotoma. Other abnormalities included depression of the visual field and paracentral scotomas.