The Goldmann Applanation Tonometry remains the gold standard for fast and reproducible IOP measurement. The advantage of the "Goldmann" method are considerable. The measurement can be carried out on the patient sitting at the slit lamp in conjunction with other routine microscopic examinations. The accuracy of the measurement is extremely high. The average deviation in any one single examination does not exceed +/- 0.5. mm HG. Furthermore, repeated measuring procedures do not reduce the ocular pressure, as no massing effects occurs. Last but not least, there are no standardization or calibration difficulties.