Single beam tone burst ultrasonic non contact tonometer and method of measuring intraocular pressure

An ultrasonic, non-contact tonometer for measuring the intraocular pressure (IOP) of an eye utilizing a single ultrasonic beam of appropriate frequency and power which simultaneously accomplishes both an ocular deformation and its measurement is provided comprising an ultrasonic transducer assembly, utilizing either a traditional head rest or a goggle-type adapter for precisely reproducible positioning of the transducer assembly relative to the eye allowing for distance and alignment adjustments, and an electronic section for signal processing, quality of precision monitoring and for the direct display of the IOP reading. A process for IOP measurement comprising the steps of continually tracking a reference phase shift between the incident and reflected beams while the instrument is in a continuous-wave low-power mode, powering up the incident beam to produce a short tone burst (amplitude surge) carrying an acoustic pressure to deform the eye and measuring the change in the phase shift of the reflected beam caused by the deformation is also provided.