The 3D tracking system of the TX-20 Tonometer features a wide range of movement, so that the examinee’s pupil can be detected easily. When in Full Auto mode, the TX-20 Tonometer is a one touch operation for IOP measurement for both eyes. Just press the start button and the unit automatically aligns and measures the intraocular pressure of both eyes. For added flexibility, the TX-20 Tonometer also includes Auto and Manual measurement modes.