tonometry /tōnom″ətrē/ , the measuring of intraocular pressure by determining the resistance of the eyeball to indentation by an applied force. Several kinds of tonometers are used. The air-puff tonometer, which does not touch the eye, records deflections of the cornea from a puff of pressurized air. The Schiötz impression and the applanation tonometers record the pressure needed to indent or flatten the corneal surface. Applanation tonometry at the slit lamp is considered most accurate. Schiötz tonometry is rarely done today.
