Glaucoma Tests: What You Need to Know Before Your Appointment

If your doctor mentioned glaucoma, you probably wonder what tests are coming up. Glaucoma is a silent disease that damages the optic nerve, so catching it early matters. The good news? Most eye doctors use quick, painless checks that give clear info about pressure, vision and nerve health.

Common Types of Glaucoma Tests

Tonometry (eye pressure test) is the most familiar. A small puff of air or a tiny probe touches the eye for a second to measure fluid pressure. It feels like a quick blink and takes less than a minute.

Ophthalmoscopy lets the doctor look at the optic nerve through a special lens. You’ll sit in a dim room while they shine a light into your eye. This shows whether the nerve looks thin or cupped, a sign of damage.

Pachymetry measures corneal thickness with an ultrasonic probe. A thinner cornea can make pressure readings look lower than they really are, so this test helps fine‑tune the results.

Visual field test (perimetry) checks for blind spots. You stare at a central dot while lights appear in different spots; you press a button each time you see one. It maps out any missing vision that glaucoma might cause.

Optical Coherence Tomography (OCT) creates a detailed cross‑section picture of the retina and optic nerve. The scanner sweeps over your eye in seconds, giving a digital map doctors use to spot early thinning.

Preparing for Your Test

You don’t need special prep for most glaucoma checks. Just avoid rubbing your eyes right before an exam and let the clinic know if you wear contact lenses—some tests work better without them.

If you take eye drops, bring them along. The doctor may want to see how they affect pressure during tonometry. Also, write down any symptoms like flashes of light or sudden vision loss; that helps guide which test is most useful.

Most clinics offer the tests in a single visit, but sometimes OCT or visual fields are scheduled later for more detail. Ask your doctor about the timeline so you can plan work or school around it.

After the exams, you’ll get a summary of pressure numbers, nerve images and any vision gaps. If anything looks off, the doctor will discuss treatment options—eye drops, laser therapy or surgery, depending on severity.

Remember, glaucoma doesn’t cause pain, so regular screening is your best defense. Even if you feel fine, getting these quick tests every year (or as advised) can keep vision loss at bay.

Got questions? Write them down before the appointment and ask the technician how each test works. Understanding what’s happening makes the whole process smoother and less intimidating.