Dynamic contour tonometry (DCT) is a new technology for noninvasive and direct measurement of intraocular pressure (IOP); its results are thought to be influenced less than those of other methods by structural characteristics of the eye. The curvature of the pressure sensing device is concave and only slightly flatter than that of the human cornea. The cornea adapts to the curvature of the transducer head, and the sensor in the centre of the adapted area measures the pressure on the other side of the cornea in the force-free range. Studies published so far suggest that DCT is less heavily dependent than applanation tonometry on the biomechanical properties of the cornea . A further advantage of DCT over other forms of tonometry is the capability of dynamic measurements over time. It is also possible to measure both the diastolic and the systolic IOD and determine the difference between the two, i.e. the ocular pulse amplitude (OPA). OPA is an indirect indicator of choroidal perfusion and reflects the condition of the arterial vascular system and the action of the heart. It could be important in the diagnosis and treatment of glaucoma.