Inclusion Criteria:  Subjects who meet any one of the following diagnostic criteria:  Diagnosis of MS, CIS,or RIS based on the 2017 revised McDonald criteria. Diagnosis of NMOSD based on the 2015 revised NMOSD consensus diagnostic criteria. Diagnosis of myelin oligodendrocyte glycoprotein (MOG)-related encephalomyelitis, optic neuritis, or other associated disease. Diagnosis of neurological disorders other than MSRD. Healthy volunteer. Age ≥18. Able to give informed consent.  Exclusion Criteria:  Patients will be excluded from the MRI portions of the study if they have a contraindication to MRI(metallic implantsor foreign bodies, claustrophobia, MRI-incompatible pacemakers, MRI- incompatible prosthetic heart valves). Patients will be excluded from the MRI portions of the study if they are pregnant, but their demographic, clinical information,and disability measures may still be captured under the study. Patients will be excluded from the visual assessment portions of the study if they have had any recent ocular surgery (within the past two months), refractive errors of greater than or equal to ±6 diopters or other eye diseases that may affect or confound OCT/OCTA measurements (ex., age-related macular degeneration, advanced geographic atrophy, diabetic retinopathy, glaucoma).