What is a peripheral vision test and what can it detect?

Has your physician suggested you get a peripheral vision test? If so, here’s what to expect from this eye test for glaucoma and other eye conditions.

This test, which may be called a peripheral vision test, a perimetry test or a visual field test, examines and measures your eyesight, including your side vision, which is known as your peripheral. This refers to those objects that you can still see from the sides of your eyes when you're focused ahead. Our peripheral is important. It helps us see who’s coming up beside us, for example.

Your eye doctor will give you the test or tests to see if there’s a pattern to any vision loss you might be experiencing. If there is, this can indicate potential eye diseases or conditions such as glaucoma, diabetes, macular degeneration, multiple sclerosis, stroke, retinal detachment and more.

Or if you’ve already been diagnosed with a condition, regular peripheral vision tests can be administered to assess any further eyesight loss.

There are a few tests involved, including:

1. Confrontation visual field exam: Your examiner will have you cover one eye and stare straight ahead with the other. You must then tell them when you can see their hand. This is often the preliminary test to examine peripheral vision and one you undergo with every eye check-up.
2. Automated perimetry: This is the most common test to examine your peripheral vision. Looking inside a perimeter (a bowl-shaped instrument sitting in front of you), this test involves pressing a button when you see flashes of light in the different areas of your peripheral vision. Don’t fret if you don’t see all the lights—not everyone does.
3. Goldmann field exam: Sitting in front of a screen with something in the centre of it, you stare at the object and tell your examiner when you see something move into your side vision.

It’s important to be honest during these exams and not pretend to see more than you actually do, so you can get a true assessment of your eye health. The examiner will assess if there’s a pattern to your vision loss, determine how wide your range of peripheral vision is, and will suggest a course of action.

Negative results can indicate things such as a tumour that’s interfering with your vision or conditions such as glaucoma (caused by pressure inside your eye that damages your optic nerve), so the results aren’t something to ignore.