0BHumphrey Visual Field Testing
1BInformation for Patients
Your doctor has planned a visual field exam for you. This test will draw a map of the back of
your eye and what you can see. The exam will be done by a computerized machine called the
Humphrey Field Analyzer. This machine is one of the best methods to measure the visual field.
The exam is not hard. This handout will tell you what to expect when you have this exam.
Since this exam draws a map of your vision, it is important that you hold your eye still and look
straight ahead at all times. Inside the machine there is a steady white light for you to look at.
Unless told otherwise, you should stare at this light at all times. The test lights will flash on and
off at different times and different places within the machine. You will be given a response
button to hold. You should press the button whenever you think you have seen a light flash. The
best time to blink is right after you have pushed the button. Some lights will be bright and some
will be dim. Some of the lights will be too dim to be seen. There will be periods of time when
you will not see anything. Don’t be alarmed by this. The machine purposely makes some of the
lights too dim. This will measure how sensitive your eye is at different areas.
During the exam, you will hear a range of noises as the light projector moves and the shutter
opens and closes. Try to ignore these noises and respond only to the lights. At times, the
machine tests your responses by either not projecting any lights (to see if you are responding to
the noises) or projecting very bright lights (to see if you are paying attention).
This exam can take up to 20 minutes for each eye. It is very important that you be seated
comfortably with your forehead pushed forward into the machine as far as possible. You should
feel relaxed with no pressure in your shoulders or neck. The light should be clearly in focus.
You should let the technician know right away if you are not comfortable or if the light is not in
focus. If you wish to rest during the exam, hold down the response button. The machine will
beep and alert the technician to pause the test.
It is hoped that this handout will make visual field testing easier for you. Talk with your doctor
or technician if you have questions.
Your health care team may have given you this information as part of your care. If so, please use it and call if you
have any questions. If this information was not given to you as part of your care, please check with your doctor. This
is not medical advice. This is not to be used for diagnosis or treatment of any medical condition. Because each
person’s health needs are different, you should talk with your doctor or others on your health care team when using
this information. If you have an emergency, please call 911. Copyright © 1/2016. University of Wisconsin Hospital
and Clinics Authority. All rights reserved. Produced by the Department of Nursing. HF#4214