(1) a bodily disturbance resulting from breathing high partial pressures of oxygen; characterized by visual and hearing abnormalities, unusual fatigue while breathing, muscular twitching, anxiety, confusion, incoordination, and convulsions; can occur when excessive quantities of oxygen are administered in patients (such as during adult respiratory distress syndrome), resulting in worsening of pulmonary infiltrates and clinical deterioration; although the mechanism for development of the condition is obscure, a disruption of enzymatic activity is likely, perhaps as a result of free radical formation. Cf.: retrolental fibroplasia (2) exposure of the lungs to greater than 60% oxygen for periods exceeding 24-48 hours can lead to severe, irreversible pulmonary fibrosis. SYN: oxygen poisoning.