A visual field test is an essential tool for detecting signs of glaucoma-induced damage to the optic nerve and identifying abnormal visual field defects caused by ocular conditions such as retinal and optic nerve diseases, as well as eyelid abnormalities like drooping lids.
This test is vital for eye doctors to diagnose, determine severity, and monitor patients with glaucoma and other eye problems. It assesses the field of vision while looking straight ahead, indicating the extent of the area the eye can see. Additionally, it measures the sensitivity of vision in different parts of the visual field, identifying any blind spots that may be present.
It measures the field of vision the eye can see while looking straight ahead, that is, how wide of an area your eye can see. It also measures the sensitivity of the vision in different parts of the visual field. The test can determine if you have blind spots in your vision.
Before your test
You should be well rested to ensure you'd be able to concentrate and give the most accurate and reliable responses during the test.
On the day of your test
If you have dry eyes, it is recommended to bring your regular eye drops and apply them 10 minutes before the start of the test.
If you had any eye procedures done recently, please inform the technician to make sure the corrective lens is selected appropriately.
Instructions will be provided if this is your first time doing the test, or if you have forgotten how to do the test. If you have any language barriers in understanding, please ask for an interpreter."
During the Test
In general, only one eye will be tested at a time and the eye not being tested will be covered with an eye patch. The test usually takes about 4 to 6 minutes per eye depending on the testing method and your responses.
Ensure that you are seated comfortably. Rest your lower back against the back rest of the chair and lean your head slightly forward. You should be able to place your chin at ease on the chin rest and look straight ahead without tilting or turning your head.
Your eye lashes should be nearly touching the corrective lens in front of your eyes. If any parts of the lens holder and/or corrective lens is/are blocking your view, please inform the technician before starting the test.
Always maintain your focus on the target light straight ahead. You should only use your peripheral or "side" vision to spot any lights that come into your view.
* Important: The test will NOT be accurate if you move your eyes!
Press the response button as soon as you see a spot of light anywhere in your vision. These spots have different degrees of brightness and the time gap between each spot may vary.
When you are feeling tired, you can blink or rest during the test. <Insert I> Press and hold the response button to pause the test and release the button to resume the test when you are ready to continue.
Tips for Performing a Reliable Visual Field Test
- Focus on the central target light straight ahead
- Wait for the spot of light to appear instead of looking for them
- Respond to all lights (except the target light) as soon as you see it
- Inform the technician if you need a break or any additional assistance
- Breathe and Blink normally during the test and don't panic if you think you have missed a point - you will have another chance!
- Imagine yourself playing a shooting star game"
- Article is contributed by Optometry, Allied Health Services -
