Understanding Visual Field Tests: Why They Matter for Your Eye Health

What Is a Visual Field Test?

A visual field test, also known as a perimetry exam, is a painless assessment conducted by an eye care professional to measure the full range of your vision. It specifically evaluates:

1. How much of your surroundings can you see without moving your eyes?
2. The clarity of your vision at different points within your field of view.

Your vision isn’t just about what’s directly in front of you. While your central vision helps you focus on details, your peripheral vision lets you detect movement and objects to the sides, above, and below. A healthy visual field means you can seamlessly see the world around you without blind spots or distortions.

Why Is a Visual Field Test Important?

The visual field eye test is commonly used to diagnose and monitor conditions like glaucoma, which can cause gradual peripheral vision loss. Since these changes often happen without noticeable symptoms, routine testing ensures early detection and effective management.

Different types of visual field tests include the Humphrey visual field exam and the Goldmann visual field exam, which assess various aspects of your vision to determine if any changes have occurred.

By undergoing regular field-of-vision eye tests at Abasa Optical, you can proactively protect your eyesight and maintain optimal eye health. If you have concerns about your vision or need a routine exam, book an appointment with us by visiting our clinic in Surrey or by calling 604-575-9141!

What Is the Purpose of a Visual Field Test?

In its early stages, glaucoma primarily affects peripheral (side) vision. Since these changes are often subtle, many people don’t notice them during daily activities, especially since one eye can compensate for another.

The visual field test is used to diagnose and monitor glaucoma. Your optometrist or ophthalmologist will conduct this test regularly to track whether the condition is stable or worsening. Various types of visual field testing machines are designed to assess your vision differently.

As glaucoma progresses, more of the peripheral vision is lost. In advanced stages, even central vision can become affected. While this typically happens later in the disease, some individuals may experience central vision loss earlier, making routine visual field testing even more essential.

Because visual field testing can have slight variations, multiple tests over time help establish a baseline and track changes more accurately, repeating the test ensures that any detected changes are fundamental and not due to testing inconsistencies. Additionally, it helps improve your familiarity with the process, making future tests easier. Most importantly, this test provides eye care professionals valuable insight into your vision and how it may change over time. It also helps determine whether your treatment plan is effective.

The test is designed to be somewhat challenging, but there’s no need to stress. Each session usually takes about 5 to 10 minutes per eye. To get the most accurate results, try to be well-rested and alert. There’s no rush—the machine adjusts your response speed to ensure a precise assessment.

What to Expect During a Visual Field Test

During the test, a trained technician will ensure you are seated comfortably in front of the testing device. If you usually wear glasses, corrective lenses will be provided as needed.

Before starting, the technician will give you clear instructions on how to take the test. They will monitor your eye position to ensure you are looking straight ahead at the fixation light. They may also adjust your posture or gently reposition your head if needed, ensuring that your upper eyelid does not obstruct your vision.

This test is crucial in detecting and managing glaucoma, helping to protect eyesight for the long term.

Visual Field Test: What to Expect

A visual field test is a straightforward, non-invasive procedure that doesn’t require any special preparation. It’s typically painless, and you likely won’t experience any side effects.

Various visual field tests share one key element: you focus on a central point and notify the examiner when you spot a light or object in your peripheral vision.

Your optometrist will guide you on where to focus your gaze to ensure accurate results.

Basic Visual Field Tests:

1. Amsler Grid

The Amsler grid consists of a pattern of straight lines that form squares. You’ll look at a dot in the centre of the grid and indicate any areas where the lines appear distorted—whether blurry, wavy, or broken. This test focuses on your central vision, providing your doctor with valuable insights into the condition of your visual field.

2. Confrontation Visual Field Test
   In this test, the optometrist sits facing you at a distance of about 1 metre (3 to 4 feet). They extend their arms outward, and you focus straight ahead. As they move one hand toward the centre, you’ll signal when you see it. This test evaluates your peripheral vision but is less precise than other methods.

Additional Types of Visual Field Tests:

You may also come across terms like kinetic or static perimetry, which are variations of peripheral vision tests.

1. Kinetic Perimetry
   This test involves the examiner moving an object through your visual field, and you notify them when you spot it. One popular test in this category is the Goldmann perimetry test.
2. Static Perimetry
   Static perimetry is used for automated peripheral vision tests. You’ll look into a bowl-shaped device and press a button when you see an object appear. Common examples of static perimetry tests include the Humphrey and Octopus tests.

Each type of visual field eye test checks the range and sensitivity of vision, helping healthcare providers diagnose various conditions affecting the eyes and brain.

Conclusion

Visual field tests are essential for spotting hidden vision problems, such as glaucoma or early signs of stroke. Catching these issues early means better treatment and preserving your eye health. If you’re noticing changes in your vision, don’t wait—schedule a test today. Visit Abasa Optical, your go-to eye clinic in Surrey, for expert care and personalized solutions. Book now and take the first step toward a healthier, clearer vision!