Dr. Quan 
What is it?
Your complete field of vision, mapped
The visual field is the entire area you can see, including central and peripheral (side) vision. A visual field test, also called perimetry, can detect problems anywhere in the visual field that may be difficult to notice on your own, since both eyes often compensate for each other. Because of this, a problem may go unnoticed until each eye is tested separately.
This test provides information no other test can. It is used to detect diseases such as glaucoma and retinitis pigmentosa, as well as neurological conditions including brain tumours, strokes, and optic nerve disorders. It also helps monitor disease progression and the effectiveness of treatment over time.
How It Works
What to expect during the test
One eye is temporarily patched while the other is tested. This ensures accurate, independent results for each eye.
You look straight ahead at a fixed target and press a buzzer whenever you see a small light appear in your peripheral vision. It is very important to keep your eyes on the central target throughout.
Each eye is usually tested in just a few minutes, for a total test time of about 20–30 minutes. A trained technician guides you through the process to ensure the most accurate reading possible.
Results are printed by the computer immediately. Your optometrist can easily identify blind spots and abnormal areas. If a test reveals an abnormal result, the doctor may recheck certain areas several times using the computer to confirm a blind spot and verify the first test was correct.
Conditions Detected
What visual field testing can find
Visual field defects, also called blind spots, can range from mild (light grey areas) to severe (black areas). Many conditions cause no noticeable symptoms until significant damage has occurred. Early detection is key.
Patient Tips
Getting the most accurate results
Take a Break if Needed
You can ask the technician to pause the test at any time. Don't push through if you're losing focus. Accuracy matters more than speed.
Book When You Feel Alert
Try to schedule your test during the time of day when you feel most attentive. Fatigue can affect your responses and reduce accuracy.
Talk to Your Doctor
If you find standard perimetry difficult, let your optometrist know. Alternative field tests may be available that are better suited to you.
Why It Matters
Untreated glaucoma: What can happen
Visual field testing is one of the most important tools for monitoring glaucoma. The lightly shaded areas on a visual field result are normal; dark areas indicate blind spots. Left untreated, these blind spots grow over time, a process that can span years or even decades, resulting in permanent, irreversible vision loss. Early detection and treatment is the only way to prevent it.
Have your Visual Field Tested
Ask about perimetry testing at your next visit. Book online or call us today.
Book an AppointmentOr call us at 1-888-381-2677, email info@drquan.ca, or fax 1-888-310-0029
* Confirm availability of visual field testing at your nearest location.