The overarching goal of this research protocol is to acquire eye-tracking, cognitive, and disease-severity metrics in multiple sclerosis (MS) patients to further build up a database of MS patients and train a machine learning classifying algorithms to identify which eye-tracking metrics-or combination thereof-can serve as reliable markers of MS disease severity and cognitive status.

This study will use a single group design in a cohort of MS patients. Eligible patients with MS will be selected and categorized based on their Expanded Disability Status Scale (EDSS) score. Patients eye movements will be captured using the patented eye-tracking technology at one single time point. In addition to the eye-tracking tests, patient phenotypes will be further detailed via brief functional and cognitive assessments using the EDSS, Brief International Cognitive Assessment for MS (BICAMS) and Multiple Sclerosis Functional Composite (MSFC). All patients will be required to participate in a single session.

Inclusion Criteria:

• Able to provide informed consent.
• Aged 18 years or older at the time of enrollment.
• Able to read in either French or English.
• Visual acuity of 20/100 in at least one eye (corrective glasses, contact lenses, surgery etc. are permitted)
• Confirmed diagnosis of MS with no signs of progressive increase in physical disability within the past six months.
• Neurological condition is medically stable during the study visit.

Exclusion Criteria:

• Evidence or medical history of psychiatric issues, which are known to also affect movements and oculomotor control.
• Presence of comorbid neurological conditions to avoid eye movement anomaly confounds (Strabismus, cranial nerve palsy, stroke-causing hemianopsia).
• Diagnosis of macular edema or other pre-existing ocular conditions that would prevent a participant from performing the eye movement assessments.
• Recent (less than three months from enrollment) start of, change of dose, or irregular use of, new prescription drugs known to influence ocular motor visual function, such as benzodiazepines, antipsychotics and anticonvulsants. Occasional use of benzodiazepines for medical procedures is permitted, at the investigator's discretion, but should not occur within a short time period prior to or during an eye movement assessment
• Diagnosis of Clinically Isolated Syndrome (CIS), Radiologically Isolated Syndrome (RIS) or Primary Progressive MS (PPMS).
• Patients who are currently experiencing a relapse or who have experienced a relapse within the last three months. A relapse is defined as appearance of a new neurological abnormality or worsening of previously stable or improving pre-existing neurological abnormality, separated by at least 30 days from onset of a preceding clinical demyelinating event. The abnormality must have been present for at least 24 hours and occurred in the absence of fever (< 37.5°C) or known infection.
• Patients who have been undergoing disease-modifying therapy for less than three months

Our target sample size for the MS group is 120. Eligible patients with MS will be selected and categorized based on their EDSS score.