The purpose of this study is to determine whether combining information from visual assessment and blood markers, as well as historical and ongoing magnetic resonance imaging (MRI) of the brain, orbit (the part of the skull where eyes are located), or spinal cord can predict disability progression due to neurological disease. Researchers hope to learn whether several biomarkers (MRI scan, blood tests, or visual assessment) can correlate with long-term disability and clinical outcomes in multiple sclerosis and related disorders (MSRD) and their response to therapy. Biomarkers may be a sign of a condition or disease and can be used to predict an individual's response to a specific treatment or risk of disability in the future.