Smooth Pursuit Eye Movements During and After Acute Exposure to Hypobaric Hypoxia

Six subjects underwent 30 min hypoxia exposure at 5000 m altitude inside a hypobaric chamber. Before and after hypoxia, they breathed 100% O 2 . Their alertness was monitored through EEG recording and no changes were detected during the procedure. Eye movements were recorded with an EOG technique before, during, and after hypoxia and analyzed for mean peak velocity gain. Results suggest that the gain seems to be affected by changes in oxygen partial pressure and that the observed gain changes and their time course during the experiment might be interpreted as signs of adaptive changes within the central nervous system in response to hypoxic stress.