(noncontact tonometer) n. an instrument that blows a puff of air at the cornea to cause flattening and hence measure intraocular pressure. It is commonly used by optometrists in tests for glaucoma.
(ophthalmotonometer) n. 1. a small instrument for measuring the pressure inside the eye. There are several types. The applanation tonometer measures the force required to flatten a known area of the cornea after a drop of local anaesthetic has made the cornea numb. A greater force is required when the pressure inside the eye is increased, and vice versa. The Goldmann applanation tonometer flattens a corneal area of 3 mm2. See also pneumotonometer. 2. an instrument for measuring pressure in some other part of the body.