How To Prepare
Tell your doctor if you or someone in your family has glaucoma or risk factors for glaucoma.
If you wear contact lenses, remove them before the test. Do not put your contacts back in for 2 hours after the test. Bring your eyeglasses to wear after the test until you can wear your contact lenses.
Loosen or remove any tight clothing around your neck. Pressure on the veins in your neck can increase the pressure inside your eyes. Stay relaxed.
How It Is Done
Tonometry takes only a few minutes to do.
Applanation (Goldmann) method
This type of tonometry is done by an ophthalmologist or an optometrist. Your doctor will use eyedrops to numb the surface of your eyes so that you will not feel the tonometer during the test. A strip of paper containing a dye (fluorescein) will be touched to your eye, or eyedrops containing the dye will be applied. The dye makes it easier for your doctor to see your cornea.
You will rest your chin on a padded support and stare straight into the microscope (slit lamp). Your doctor sits in front of you and shines a bright light into your eye. Your doctor gently touches the tonometer probe to your eye. Your doctor checks the tension dial on the tonometer that measures the IOP of your eye.
Do not rub your eyes for 30 minutes until the numbing medicine has worn off.
Electronic indentation method
Electronic tonometry can be done by a technician, an optometrist, an ophthalmologist, or a family medicine doctor. Your doctor will use eyedrops to numb the surface of your eyes so that you will not feel the tonometer during the test.
You will stare straight ahead, or sometimes look down. Your doctor gently touches the tonometer probe to your eye. Several readings will be taken on each eye. You will hear a clicking sound each time a reading is obtained. After enough accurate readings have been obtained, a beep will sound, and the averaged IOP measurement will appear on the instrument's display panel.