| Tonometry | |
|---|---|
 A patient in front of a tonometer | |
| Specialty | Optometry |
| ICD-9-CM | 89.11 |
| MeSH | D014065 |
| MedlinePlus | 003447 |
Tonometry is the procedure that eye care professionals perform to determine the intraocular pressure (IOP), the fluid pressure inside the eye. It is an important test in the evaluation of patients at risk from glaucoma.[1] Most tonometers are calibrated to measure pressure in millimeters of mercury (mmHg), with the normal eye pressure range between 10 and 21 mmHg (13–28 hPa).