RESULTS: One patient was a 77-year-old obese woman with a history of chronic obstructive pulmonary disease (COPD), hypertension and diabetes. The other was a 75-year-old thin man with interstitial pneumonitis, peptic ulcer. Both patients denied the history of glaucoma and other ocular diseases. The female patient was undergoing no-invasive positive pressure mechanical ventilation. The mode was BiPAP, IPAP 10cmH2O, EPAP 4cmH2O. She reported blind in the right eye 8 days after mechanical ventilation. The male patient was undergoing endotracheal intubation and positive pressure mechanical ventilation. The mode was A/C, FiO2 60% PEEP 5cmH2O, Ps 20cmH2O, f 15cmH2O. He reported tears and pain in both eyes 7 days after mechanical ventilation. The two patients were diagnosed as acute glaucoma. After treatment one patient’s eyesight recovered, but the other lost her sight.