A tonometer is an ophthalmic device used to measure the intra-ocular pressure of the eye and determine if the patient is at risk of glaucoma.
The eye to be examined is anaesthetised and the foot plate of the tonometer is pressed gently onto the cornea. By this method, the ophthalmologist is able to measure the patient's intra-ocular pressure in mmHg. ]]> John Weiss & Son, Ltd.; 1787-; Surgical instrument makers]]>