OVER 30% OF AMERICAN ASTRONAUTS HAVE DEVELOPED OCULAR REFRACTION CHANGE AFTER LONG DURATION SPACE FLIGHT ON THE INTERNATIONAL SPACE STATION (ISS) (65). RECENT FINDINGS HAVEALSO INCLUDED STRUCTURAL CHANGES OF THE EYE (PAPILLEDEMA GLOBE FLATTENING CHOROIDAL FOLDS) AND THE OPTIC NERVE (SHEATH DILATATION TORTUOSITY AND KINKING) AS WELL AS IMAGING SIGNS AND LUMBAR PUNCTURE DATA INDICATIVE OF ELEVATED INTRACRANIAL PRESSURE (ICP) (56; 65). WHILE SHORT DURATION SPACE FLIGHT IS ALSO CHARACTERIZED BY VISION DISTURBANCES THESE ARE GENERALLY TRANSIENT AND DO NOT APPEAR TO HAVE LASTING IMPACTS ON THE STRUCTURE OR FUNCTIONOF THE EYE. CHANGES IN VISION EYE AND ADNEXA MORPHOLOGY ARE HYPOTHESIZED TO BE THE RESULT OF SPACE FLIGHT-INDUCED CEPHALAD FLUID SHIFTS AND TRANSIENTLY ELEVATED INTRACRANIALPRESSURE (65). THIS HYPOTHESIS HOWEVER HAS NOT BEEN SYSTEMATICALLY TESTED. IN EARLIER ANECDOTAL PUBLICATIONS ICP ELEVATION IN LONG-DURATION SPACE FLIGHT HAS BEEN INFERRED BUT WITHOUT ASSOCIATION WITH STRUCTURAL OR FUNCTIONAL CHANGES OF THE EYE (74). FURTHERMORE WHILE FLUID SHIFTS AND COMPARTMENTALIZATION DURING SHORT-DURATION SPACE FLIGHT (SPACE SHUTTLE MISSIONS) HAVE BEEN STUDIED THE FLUID DISTRIBUTION PATTERNS AND THEIR EFFECTS ON INTRACRANIAL PRESSURE OR THE STRUCTURE AND FUNCTION OF THE SENSORY ORGANS IN THE COURSE OF LONG-DURATION SPACE FLIGHT ARE NOT WELL KNOWN.