The Eye in Space: Optometry’s Role in Managing Vision Challenges in Microgravity

Home > 2025, Vol. 11 No. 02 > The Eye in Space: Optometry’s Role in Managing Vision Challenges in Microgravity

Published: November 28, 2025

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Authors

Mahak, Sachitanand Singh and Nakul Sankhayadhar

DOI Number
https://doi.org/10.15415/jmrh.2025.112009

Keywords
Spaceflight associated neuro-ocular syndrome, Optometry, Microgravity, Space medicine, Vision challenges

Abstract

Background: Spaceflight-Associated Neuro-Ocular Syndrome (SANS) is a major health threat to astronauts experiencing long-duration spaceflight. SANS is characterized by optic disc edema, globe flattening, choroidal folds, hyperopic shifts, and increased retinal thickness. These changes are primarily caused by cephalad fluid shifts and altered intracranial pressure (ICP), all of which have implications for visual function, mission safety, and long-term ocular health.

Purpose: This paper reviews the literature related to the cause, diagnosis, treatment, and optometric consequences of SANS and discusses the essential role of optometry in the eye care of astronauts, as well as possible translational applications for eye problems on Earth.

Methods: A systematic narrative review was conducted using the databases PubMed, Scopus, Web of Science, and Google Scholar over the period of 2010–2025. Studies focused on ocular changes in astronauts, imaging modalities (OCT, MRI, ultrasonography), and countermeasures. Results were categorized into diagnostic modalities, pathophysiology, interventions, visual performance, and optometric implications.

Results: Approximately 60–69% of long-duration astronauts exhibited visual changes compared to 29% for shorter missions. Similar studies failed to replicate the same direction of the SANS condition, although modeling found evidence of orbital fat edema and the risk of structural vulnerability to increased intracranial pressure or IOP. Diagnostic methods are noninvasive, thus potentially improving utilization in space. Diagnostic methods such as OCT, ultrasonography, fundus photography, and AI-facilitated algorithms likely have more sensitivity than traditional methods. Countermeasures such as artificial gravity, lower body negative pressure, and fluid-shifting garments partially mitigated the incidence of SANS. Functional performance included decreased contrast sensitivity, loss of stereoacuity, and transient refractive shift.

Conclusion: SANS is a multifaceted syndrome that encompasses intracranial pressure, fluid mechanisms, vascular and glymphatic drainage, anatomical considerations, and environmental stressors. Optometry plays a critical role in diagnosing, monitoring, and rehabilitation and can impart translational information related to disorders such as idiopathic intracranial hypertension and glaucoma.

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How to Cite

Mahak, Sachitanand Singh and Nakul Sankhayadhar. The Eye in Space: Optometry’s Role in Managing Vision Challenges in Microgravity. J. Multidiscip. Res. Healthcare. 2025, 11, 71-82

The Eye in Space: Optometry’s Role in Managing Vision Challenges in Microgravity

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