Ophthalmic tonometer, line-powered

Intended purpose

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 millimeter (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. This device is handheld battery-operated but changed by a charging station from mains power.