How It Is Done continued...
This type of
tonometry is usually 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.
You will lie on your back on an
examination table. Try to stay relaxed and not cough, blink, or squeeze your
eyelids together because these movements can increase the pressure inside your
You will look up at a spot on the ceiling. Your doctor will
gently touch the tonometer to your eye and hold it there for a few seconds. The
test may be done on the other eye also.
Do not rub your eyes for
30 minutes until the numbing medicine has worn off.
How It Feels
Tonometry should not cause any eye pain.
Your doctor will use eyedrops to numb the surface of your eyes so that you will
not feel the tonometer during the test. You may have a scratchy feeling on your
cornea. This usually goes away in 24 hours.
Some people become
anxious when the tonometer needs to be touched to the eye. In air-puff
tonometry, only a puff of air touches the eye.
There is a very slight risk that your cornea
may be scratched during the methods that involve touching a tonometer to your
eye. Rubbing your eyes before the anesthesia wears off increases the risk of
scratching the cornea. If tonometry causes a scratch on the cornea, your eye
may be uncomfortable until the scratch heals, which normally takes about a
There is also a very small risk of an eye infection or an
allergic reaction to the eyedrops used to numb your
With the air-puff (noncontact) method, there is no risk of
scratches or infection, since nothing but air touches your eyes. But this
method is not the best way to measure intraocular pressure.
should not have any eye pain or vision problems after tonometry. Call your
doctor if you feel any eye pain during the test or for 48 hours after the
A tonometry test measures the pressure
inside your eye, which is called intraocular pressure (IOP). This test is used
to check for
Normal eye pressure is
different for each person and is usually higher just after you wake up. IOP
changes more in people who have glaucoma. Women usually have a higher IOP than
men, and IOP normally gets higher as you get older.
- A high IOP may mean that you have glaucoma or
that you are at high risk for developing glaucoma. People who have ongoing
pressures above 27 mm Hg usually develop glaucoma unless the pressure is
lowered with medicines.
- People who have an ongoing IOP higher than
21 mm Hg but do not have
optic nerve damage have a condition called ocular
hypertension. These people may be at risk for developing glaucoma over