in such a manner that when it was pressed, the gas could flow out of an opening at a rate of
400 ml/min. The testee's eyes were applied to the opening during 300 seconds. The
irritant concentrations were measured through the flowing gas in this way. The testee's eye
was observed with the slit-lamp before and after the experiment. The numbers of testees
were a range between 10 and 22 and thre was the range 0 f age from 19 years old to 32
years old. The gases used in this experiment and their measurements3)-S) are shown in Table