Currently, it is not known if neuronal loss in the retina and brain after mTBI in either veterans or in the civilian population (especially in sports-related concussion) continues to progress over time. Closing this knowledge gap will be important for understanding and treating TBIrelated visual symptoms and for establishing whether ocular biomarkers such as the pupil light reflex and optical coherence tomography (OCT) can be used to predict risk of CNS dysfunction and its progression over time.