Digital tonometry measures the pressure inside your eye, known as intraocular pressure (IOP). This is one of the most important measurements in a routine eye exam, since elevated eye pressure is a key risk factor for glaucoma, a condition that can damage the optic nerve and lead to vision loss if left unaddressed. We use one or more digital tonometry methods to check this pressure quickly and comfortably.
Methods We Use
There are a few different ways to measure eye pressure, and your provider will choose the method best suited to your exam:
- Goldmann Applanation Tonometry: Considered the clinical standard, this method uses a small probe that gently touches the surface of the eye after numbing drops are applied, measuring the force needed to flatten a small area of the cornea.
- iCare Rebound Tonometry: A lightweight probe briefly and gently touches the eye and bounces back, with the device calculating pressure from the rebound. This method typically does not require numbing drops.
- Non-Contact Tonometry: Often called the "air puff" test, this method uses a brief pulse of air directed at the eye to measure pressure without any instrument touching the eye at all.
What to Expect
Whichever method is used, the test itself takes only a few seconds per eye and involves no real discomfort. If a contact-based method is used, numbing drops may cause your eye to feel slightly different for a few minutes afterward, but there's no downtime and you can resume normal activities right away.
Why It Matters
Eye pressure can be elevated well before any symptoms or vision changes appear, which is why tonometry is a routine part of comprehensive eye exams rather than something reserved for patients with known concerns. Your provider will interpret your pressure reading alongside other findings, such as optic nerve appearance and corneal thickness, to assess your overall risk and determine whether further glaucoma testing or monitoring is appropriate.