Updated January 01, 2014.

Definition:

Measurement of the fluid pressure inside of the eye. Eye fluids circulate and eventually drain out of the eye. If the drainage system becomes clogged or if too much fluid is produced, pressure inside the eye can build up. Having higher than normal eye pressure places a person at a higher risk for glaucoma.

Intraocular pressure is measured with an instrument called a "tonometer."

Also Known As: IOP (Intraocular pressure)

Alternate Spellings: Intra-ocular Pressure