What is "intraocular pressure"

n. (context physiology English) The fluid pressure inside the eye.

n. pressure inside the eyeball;regulated by resistance to the outward flow of aqueous humor; "glaucoma results from increased intraocular pressure"

Intraocular pressure (IOP) is the fluid pressure inside the eye. Tonometry is the method eye care professionals use to determine this. IOP is an important aspect in the evaluation of patients at risk from glaucoma. Most tonometers are calibrated to measure pressure in millimeters of mercury ( mmHg).