Intraocular pressure (IOP) is a measurement of the fluid pressure of the eye.
Your eyes produce a fluid called aqueous humor. This fluid flows into your eye and the same amount should drain out through a drainage area within the eye. This process keeps the intraocular pressure or pressure in your eye stable.
However, if the drainage system in the eye is not functioning properly, the aqueous humour builds up. This build up of fluid causes the intraocular pressure to rise.
If this elevated pressure is left untreated, it can cause damage to the optic nerve. This is often how glaucoma develops.
As part of a complete eye exam, your ophthalmologist or an assistant will measure your eye pressure.
How Is Eye Pressure Measured?
Topical anaesthetic eye drops are placed into your eyes to numb them.
Then the doctor or assistant gently touches the front surface of your eye with a handheld device that measures the eye pressure.
Each person’s eye pressure is different, and there is no single correct pressure for any person. Generally, the range for normal pressure is between 10 and 21 mmHG.
Your ophthalmologist will determine the eye pressure range that is within a healthy range, and is specific to you.