Spaceflight Associated Neuro-Ocular Syndrome (SANS) is a distinct set of neuro-ophthalmic clinical and imaging abnormalities identified in astronauts during long-duration spaceflight. Optic disc edema, posterior globe flattening, retinal nerve layer fiber thickening, optic nerve sheath distension, and hyperopic shift were among the various findings. SANS was a major impediment to deep space travel; nevertheless, the specific pathophysiology was being studied by the researchers. While there was in-flight imagery aboard the International Space Station, continual monitoring had limitations. NASA had funded the development of a head-mounted display, multi-modal visual assessment system to efficiently document the subtle changes that occurred in SANS; the novel device integrated visual acuity, visual field, contrast sensitivity, and metamorphopsia data (indirect indications) with known terrestrial neuro-ophthalmic imaging (direct indications) from astronauts as well as terrestrial analogs. The visual evaluation gadget allowed for immediate in-flight monitoring of SANS symptoms as well as tools for the terrestrial creation of countermeasures by mapping these two indicators. 

Researchers were conducting pilot research on the multi-modal visual assessment device in healthy people in order to examine its validity and reliability. In the preliminary investigation, the method was compared to routine vision exams used in clinical practice.