St. John of Jerusalem Eye Hospital, East Jerusalem ^Company

The causes of this phenomenon, known as Space Flight-Associated Neuro-Ocular Syndrome (SANS) are unclear, partly due to the fact that it is difficult to conduct good quality monitoring while on the International Space Station. Since this phenomenon places the crews of prolonged missions in jeopardy, it is imperative that the causes of SANS be understood and a solution be found, before manned missions can be launched to explore deep space.