AUTO REF/KERATO/TONOMETER Model TONOREF II is designed to singly perform objective refraction, corneal shape measurement, and non-contact tonometry measurement by incorporating a standard auto ref/keratometer and non-contact tonometer into one unit. The objective refraction function measures spherical powers, cylindrical powers and cylinder axis. The corneal shape measurement function measures the radius of corneal curvature (corneal refractive powers), the direction of the steepest meridian, and the amount of corneal astigmatism. The non-contact tonometry function measures the intraocular pressure without contacting the eye.
An ophthalmic, line-powered, measuring instrument used for determining the intraocular pressure (IOP) by exerting an external force against the eye which provides a reading of the resistance of the tunica of the eye to deformation (the extent of corneal indentation) which is expressed in millimetre(s) of mercury (mmHg). It typically has no contact with the eye and can use various techniques, e.g., the air-puff tonometer records deflections of the cornea from a puff of pressurized air; the applanation tonometer records the indentation pressure in thousands of a second. It is used for the diagnosis of glaucoma, designed for table top use and may provide the data on a screen and/or a print-out.
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