Macias BR, Ferguson CR, Patel N, et al. - Experts aspired to explore whether the manifestation of spaceflight-associated neuro-ocular syndrome worsens during International Space Station missions exceeding the present 4- to 6-month duration. From March 2015 to September 2016, 2 crew members partook in this investigation. Over the course of a year in low Earth orbit aboard the International Space Station, this study records the late development of mild optic disc edema in 1 crew member and the progressive development of choroidal folds and optic disc edema in another crew member. The ocular risk associated with 4 to 6 months of spaceflight has been defined in previous studies. Further monitoring of astronaut ocular health on spaceflight missions longer than 6 months may be warranted as future spaceflight missions are expected to increase in duration and extend beyond low Earth orbit.