Is visual field or electrophysiology a better functional assessment of vision in space?

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Regardless of the pathophysiology of optic disc swelling present in spaceflight-associated neuro-ocular syndrome (SANS), the effect on the function of the optic nerve has not been established. OCT of the retinal nerve fiber layer provides a structural correlate for disc edema but does not provide functional data. The challenge in defining a functional metric is, in part, related to the inability of current clinical metrics, including best corrected visual acuity and visual fields, to detect subtle abnormalities in vision. Thus, while