ESA astronaut, Alexander Gerst uses the Optical Coherence Tomography (OCT) camera during an Ocular Health (OH) vision test
European Space Agency astronaut Alexander Gerst, Expedition 40 flight engineer, uses the Optical Coherence Tomography (OCT) camera during an Ocular Health (OH) vision test in the Harmony node of the International Space Station. The OH experiment observes and seeks to understand vision changes during long-term space missions.