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Good Hope Hospital Eye Clinic
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Visual Field Testing
Glaucoma pages
What is a visual field test?
A visual field test measures how much 'side' vision you have. It is a straightforward test, painless, and does not involve eye drops. Essentially lights are flashed on, and you have to press a button whenever you see the light. Your head is kept still.. you have to rest your chin on a a chin rest. The lights are bright or dim at different stages of the test. Some of the flashes are purely to check you are concentrating.

(Here is an online website that enables you to test you own visual field.)

How long will it take?

Each eye is tested separately, and you should allow 15-45 minutes to have the whole test.

 

Driving visual field test

DVLA website...click hereA doctor may ask only for a driving licence visual field test, which takes 5-10 minutes. Most of these tests are carried out at the instruction of the Driving and Vehicle Licencing Centre (DVLA) in Swansea, and if requested by the DVLA the results will be sent to them. (See 'What happens to the results?' below). The DVLA sends a letter confirming the patients' permission to release the results (which the patient sent to them previously). If you have just asked for a driving test or the clinic doctor advised you have one, you will be informed of the result by the clinic doctor, in writing, in a few weeks. In this instance the DVLA is not informed of the result (as they did not request the test), as this is the patient's responsibility.

Here is the  DVLA website. Here is the page for car drivers for further details. You must notify the DVLA if you have laser treatment of both eyes, or if you have laser to your one good eye.

What equipment is used?
Normally the test is carried out by a computerised machine, a Humphrey. Occasionally the manual test has to be used, a Goldman. Again, for each test you have to look at a central point, and have to press a buzzer each time you see the light.

See videos Goldmann 1.6mb or computerised Humphrey 600kb (windows media) or Quicktime (550kb)

What do you need to bring?

You need to bring your reading or bi-focal glasses you have. (But always bring your distance and reading glasses to every eye clinic visit.)

 

Who will do the test?

Either the glaucoma technician or an orthoptist or optometrist will do the test.

What happens to the results?

The results are placed in your notes and the ophthalmologist will review the notes at your next consultation. (see Driving visual fields above).

Reduction in the mean deviation of Humphrey fields is significant,

.

When is this test done?
Usually the test is advised at you previous consultation. It is one of the most important tests for glaucoma. If your side vision gets worse, you may need more drops to lower the eye pressure further. It is usually carried out before the NEXT appointment, to help the doctor advise you on the treatment that would be helpful.

 

If you cannot keep the appointment
It is vital that you let the eye clinic know (see appointments) so an alternative appointment can be arranged, and the appointment offered to someone else, so you have to wait less time for the next appointment.

 

Gabapentin
There are reports that Gabapentin can affect visual field. If you use Gabapentin, have an eye examination at your optometrist and ask for a visual field test. If the visual fields are reduced, let your GP know.

----------------------Eye pages website feedback -----this page edited December 2007----------------------