Ocular Changes in Human Spaceflight.

Spaceflight presents unique challenges to ocular health, with astronauts experiencing a range of visual disturbances in the setting of microgravity, radiation exposure, and other environmental factors. This review synthesizes knowledge about how spaceflight affects ocular anatomy and function. We outline the diagnostic and therapeutic limitations in microgravity, including constraints on imaging modalities, intracranial pressure measurement, and drug delivery. In addition, we examine common spaceflight-associated ocular pathologies, including spaceflight-associated neuro-ocular syndrome, corneal epithelial disruption, possible radiation-associated lens changes, and retinal or choroidal alterations. Drawing from evidence across human missions, terrestrial analogs, and experimental models, this review emphasizes the critical importance of vision to astronaut safety and mission success. Future directions include long-term ocular health monitoring, advancement of in-flight diagnostic capabilities, and multidisciplinary strategies to safeguard astronaut vision.