Understanding Intraocular Pressure (IOP) - An Important Eye Health Metric Intraocular pressure, often abbreviated as IOP, is a critical metric in eye health. It signifies the pressure of the fluid within the eye and is measured in millimeters of mercury (mmHg). Knowing the significance of IOP is essential for maintaining good eye health and preventing eye conditions like glaucoma.   Why Is Intraocular Pressure Important IOP is crucial because it reflects the equilibrium between the production of fluid inside the eye and its efficient drainage. To determine whether your IOP is within the normal range, you must undergo a tonometry examination. This test is commonly conducted in both public and private healthcare facilities.   Normal IOP Range Normal IOP typically falls between 12 to 20 mmHg. When the pressure within the eye exceeds 21 mmHg, it is considered abnormally high. Elevated IOP can be an early indicator of glaucoma, a serious eye condition that can lead to vision loss if not properly managed.   The Anatomy of Intraocular Pressure Inside the eye, there is a specific structure known as the Anterior Chamber. This chamber is situated between the cornea and the iris. It contains a clear fluid called aqueous humor. Aqueous humor flows into the anterior chamber and drains through a narrow-angle between the iris and the trabecular meshwork, which is the black part of the eye. From there, it enters small blood vessels outside the eye, providing oxygen and essential nutrients to the surrounding eye tissues.