Normal intra-ocular pressure.

INTRA-ocuLAR pressure varies from individual to individual, from right eye to left eye, and from time to time. Many manometric studies have been made on experimental animals but observations on human eyes have been few: Wessely (1915, 1916) found an average of 22 5 and 18X5 mm. Hg, and Seidel (1922) one of 20 and 25 5 mm. Hg. Tonometric studies of human eyes, however, have been many; the results range from 12 to 35 mnm Hg (Table I), and the normal average may be taken between 15 to 35 mm. Hg. TABLE I TONOMETRIC RECORD OF INTRA-OCULAR PRESSURE (mm. Hg)