Dr. Griffiths goes above and beyond in her care, making sure her patients feel comfortable and well-informed every step of the way. If you are looking for an outstanding ophthalmologist, look no further, Dr. Griffiths is fantastic!
Jagdish J
Visual Field Testing for Glaucoma and Other Eye Diseases
Who Should Have Visual Field Testing
Some people need visual field testing because of symptoms they are already experiencing, while others need it because of risk factors that make silent eye disease more likely. Understanding where you fall helps us recommend the right testing schedule for you.
If you notice a missing area in your vision, a shadow that does not go away, a curtain or veil over part of your sight, or difficulty seeing objects on one side, contact our office promptly for evaluation. These symptoms can sometimes indicate serious acute conditions such as retinal detachment, and they should not wait for a routine appointment.
- A new curtain, veil, or shadow over your vision combined with flashes or floaters requires same-day evaluation
- Sudden one-sided vision loss with neurological symptoms such as weakness, facial droop, or speech difficulty requires emergency care right away
- Bumping into door frames, missing steps, or difficulty seeing objects to one side warrants prompt examination
- Letters that disappear when reading or wavy lines on a grid should be reported to our office
Some people face a higher likelihood of developing glaucoma and benefit from visual field testing even without any symptoms. If any of the following apply to you, talk with our eye doctors about establishing a baseline test.
- Age over 60
- Family history of glaucoma
- African or Hispanic ancestry
- High myopia (nearsightedness)
- Thin central corneas or history of eye trauma
- Use of corticosteroid medications in any form
- Conditions such as pseudoexfoliation, pigment dispersion, or obstructive sleep apnea
- Asian ancestry combined with farsightedness, which raises angle-closure risk
We generally recommend establishing a baseline in your 40s if you have risk factors, and earlier if findings during your exam raise concern. The earlier we detect glaucoma, the better our chances of preserving your sight for decades.
Sudden severe headaches with vision changes, new double vision, or loss of vision on one side can signal problems involving the brain or optic nerve pathways. For any acute neurological symptoms, emergency evaluation always comes first. Visual field testing helps us localize where along the visual pathway a problem may exist, and we work closely with neurologists and neurosurgeons when results suggest a condition beyond the eye itself.
Visual field testing is not required for every asymptomatic adult, but it becomes an important part of regular care once risk factors or clinical findings are present. Our eye doctors will recommend an appropriate testing schedule based on your individual situation.
- Annual or biannual testing for patients with confirmed glaucoma
- Every one to two years for glaucoma suspects or borderline findings
- Baseline testing around age 40 with significant risk factors
- More frequent testing if results show progression or after a change in treatment
Types of Visual Field Tests We Use
Several different methods are available for measuring the visual field, and the right choice depends on your condition, your ability to cooperate with testing, and what information we need. Our eye doctors select the approach that gives us the most reliable and useful results for your situation.
Automated perimetry is the most widely used method for detecting and monitoring glaucoma. You sit at a bowl-shaped machine, focus on a central target, and press a button each time you see a small light flash in your peripheral vision. The machine records where you see lights and where you miss them, then builds a detailed sensitivity map of your entire visual field.
Because this test is highly standardized, results are easy to compare from visit to visit, making it ideal for tracking whether glaucoma is stable or progressing.
- The 24-2 and 24-2C patterns are standard for glaucoma monitoring
- The 10-2 pattern focuses on the central field, which is important in advanced disease
- The 30-2 pattern covers a wider area and is useful for neurological evaluations
- Testing algorithms such as SITA Standard, SITA Fast, and SITA Faster balance speed with accuracy
Frequency doubling technology, or FDT, presents flickering black-and-white patterns that stimulate specific nerve cells in your retina. Glaucoma often damages these cells early in the disease, so FDT can sometimes reveal vision loss before standard automated perimetry does. We may use it as a screening tool or alongside traditional testing when we suspect glaucoma but standard results still appear normal.
FDT finishes quickly and is comfortable for most patients. Any abnormal result should be confirmed with standard automated perimetry before treatment decisions are made.
Confrontation testing is a simple, quick check that our eye doctors perform without any equipment. You cover one eye, look at the examiner, and respond when you see fingers or hand motion in each quadrant of your vision. While it is not sensitive enough to detect subtle glaucoma changes, it is a useful screening tool during a routine examination and can identify large field defects that need urgent follow-up.
An Amsler grid is a simple paper chart with a grid of horizontal and vertical lines and a small dot in the center. You focus on the center dot and note whether any lines appear wavy, blurry, or missing. This test is especially useful for detecting changes from macular degeneration or other conditions affecting central vision. We often send one home with you so you can monitor your vision between appointments, and you should contact us right away if you notice new distortion or missing squares.
Goldmann perimetry uses a large illuminated dome and a trained technician who moves a light from outside your field of view inward until you detect it. This manual approach offers flexibility for patients who cannot complete automated testing, including children or those with very advanced vision loss. It is also helpful for mapping unusual field defects that automated machines may miss.
Although Goldmann perimetry is less commonly used today, it remains a valuable option in specific clinical situations, and our eye doctors will recommend it when it is the best fit for your needs.
What to Expect During Your Visual Field Test
Knowing what will happen during your test helps you feel more comfortable and perform your best. A relaxed, attentive patient produces the most reliable results, and our team will walk you through every step.
No special preparation is required for a visual field test. Bring your current glasses or contact lenses so your vision is as clear as possible during the test. Try to schedule the appointment at a time when you feel rested and alert, since fatigue can affect your responses and the reliability of results.
- Bring your current eyeglasses or contact lenses
- Let us know if your eyelids droop or your brows hang low, as we may gently tape them to prevent them from blocking your upper field
- Mention any medications you take that might affect your vision or concentration
- Plan for about 30 minutes total, including setup time
You will rest your chin and forehead on supports at the testing machine, one eye is covered with a patch, and you focus on a small target light in the center of the bowl. The room is usually dimmed so the faint test lights are easier to see. A technician will explain the instructions and start the test once you feel ready.
The machine presents lights of varying brightness in random locations throughout the bowl. Your job is to press the handheld button every time you detect a flash, even if you only barely see it. You do not need to move your head or search for the lights. Just keep your gaze steady on the center target and respond when you notice something.
Each eye typically takes between five and ten minutes, so testing both eyes usually lasts fifteen to twenty minutes in total. Some detailed tests may run slightly longer, but most patients complete the full process within half an hour including setup. If you need a brief pause, the technician can stop the test, though completing each eye in one sitting produces the most accurate results.
Keeping your gaze fixed on the central target throughout the test is the single most important thing you can do for accuracy. Looking away creates false defects that can resemble real disease. Blinking normally is fine and will not affect the results.
- Take a slow breath and relax your shoulders before the test begins
- Blink as needed but keep your eyes focused on the center target
- Press the button even for very faint lights you are not fully sure about
- Tell the technician immediately if you feel uncomfortable or need to pause
Understanding Your Visual Field Test Results
After your test, we review a printed map showing the sensitivity of different areas of your visual field. Understanding what this map reveals helps you feel confident about your diagnosis and your care plan.
The map displays shaded or numbered zones across your visual field. Darker areas or lower numbers indicate spots where the eye is less sensitive, meaning those lights were harder to detect. Lighter areas or higher numbers represent normal sensitivity. We also review reliability scores, including how often you pressed the button when no light appeared, how often you missed a clearly visible light, and how often your gaze wandered from the center.
We use summary indices such as Mean Deviation, Pattern Standard Deviation, Visual Field Index, and the Glaucoma Hemifield Test to help quantify and interpret your result within the context of your overall eye health.
A healthy visual field shows even sensitivity across most of the map, with a natural gap where the optic nerve enters the eye, called the blind spot. Sensitivity is generally highest in the center and tapers slightly toward the edges. Everyone has some natural variation, and our eye doctors compare your results to age-matched norms before drawing any conclusions. A minor deviation on a single test is not automatically a cause for concern, especially on a first visit.
Glaucoma typically causes defects in the upper or lower half of the visual field, often starting near the nose and sparing central vision until the disease is advanced. A curved defect that arcs from the blind spot outward, called an arcuate scotoma, is a classic glaucoma pattern. An uneven boundary between the upper and lower halves on the nasal side, called a nasal step, is another common finding.
- Defects that respect the horizontal midline of the visual field
- Gradual deepening of existing scotomas over months or years
- Field loss that matches structural damage to the optic nerve seen during examination
- Early changes often appear in the area ten to twenty degrees from central fixation
- Central defects within the inner ten degrees can appear early, particularly in normal-tension glaucoma
Not every shadow or defect on a visual field test represents true disease. Technical and patient factors can create patterns that mimic real damage. Recognizing these possibilities helps us interpret results accurately and avoid unnecessary concern.
- Drooping eyelids or low brows can create a false defect in the upper field
- A mispositioned trial lens can produce a ring-shaped artifact
- Cataracts or small pupils can reduce sensitivity across the entire field
- Fatigue or inattention can create scattered losses
- First-time tests are often less reliable due to a learning effect, and results tend to improve on repeat visits
Retinal diseases such as macular degeneration cause central field loss or distortion, while peripheral retinal damage produces defects that correspond to the affected area of the retina. Neurological conditions often produce defects that respect the vertical midline of the visual field, such as losing the right half of both visual fields after a stroke on the left side of the brain. Pituitary tumors classically cause loss of both outer halves of the visual field because the tumor compresses the crossing optic nerve fibers at the base of the brain. These distinctive patterns guide us toward the correct diagnosis and the most appropriate next steps.
A single test provides a snapshot, but comparing multiple tests over months and years reveals whether your vision is stable or worsening. Progression analysis software highlights areas of consistent change, helping us decide whether your current treatment is working or needs adjustment. We generally confirm new defects on at least two reliable tests before changing treatment, unless urgent clinical findings require immediate action. Staying on your recommended testing schedule gives us the data we need to protect your sight.
What Happens After Your Visual Field Test
Your visual field results are reviewed in the context of your full eye examination, and we will discuss what they mean for your care. Depending on what we find, we may recommend additional imaging, a change in treatment, or a referral to a specialist.
When visual field results show defects, we often order additional tests to clarify the cause. Optical coherence tomography, or OCT, scans the layers of your retina and optic nerve to reveal structural damage that corresponds to your functional field loss. Other tests help us assess glaucoma risk and severity more completely.
- OCT imaging to measure nerve fiber layer and ganglion cell thickness
- Gonioscopy to examine the drainage angle inside your eye
- Dilated fundus examination to inspect the optic disc and retina
- Corneal thickness measurement, called pachymetry, to refine glaucoma risk assessment
- MRI or CT imaging if results suggest a brain or optic nerve lesion
- Intraocular pressure monitoring when pressure spikes are suspected
When glaucoma is diagnosed based on visual field loss and other findings, treatment focuses on lowering intraocular pressure to slow or stop further damage. Our eye doctors offer a range of options depending on disease severity, anatomy, and patient preference. Prescription eye drops or Selective Laser Trabeculoplasty, known as SLT, are both established first-line approaches. SLT uses a targeted laser to improve fluid drainage from the eye and can reduce the need for daily drops.
For patients with certain anatomical concerns, a YAG Laser Peripheral Iridotomy, or YAG PI, may be recommended to reduce the risk of angle-closure glaucoma. When drops and laser do not achieve adequate pressure control, or when glaucoma is more advanced, Minimally Invasive Glaucoma Surgery, including a procedure called goniotomy, may be considered, often in combination with cataract surgery. More complex glaucoma cases are referred to appropriate specialists, and we remain an active part of your care team throughout. The goal of all treatment is to preserve the vision you have, because glaucoma damage cannot be reversed.
Testing frequency depends on your diagnosis and how stable your condition is. Patients with confirmed glaucoma typically need visual field tests every six to twelve months. Glaucoma suspects or those with borderline results are usually tested every twelve to twenty-four months. If your condition is progressing or your treatment has changed recently, we may test more often until stability is confirmed.
Consistent follow-up is essential. Missing appointments can allow silent progression that permanently reduces the vision you could have protected.
Certain findings require immediate action rather than a scheduled follow-up. A sudden loss of half your visual field combined with headache or neurological symptoms raises concern for stroke or bleeding and requires emergency imaging. A new curtain or veil over your vision with flashes or floaters raises concern for retinal detachment and requires same-day evaluation. Do not wait for a routine appointment if you experience any of these symptoms. We will contact you promptly if your test results show anything that warrants urgent attention, and you should reach out to us immediately if new vision symptoms develop between visits.
If your field defect points to a condition beyond the eye itself, we will refer you to the appropriate specialist, such as a neurologist, neuro-ophthalmologist, or neurosurgeon. Retinal specialists manage conditions that cause central field loss, and complex or advanced glaucoma cases are referred to glaucoma subspecialists when needed. We stay involved in your care and coordinate with other providers to make sure you receive thorough, connected treatment.
Frequently Asked Questions
Here are answers to questions our patients often ask about visual field testing that go beyond the basics covered above.
You should bring your glasses, but we will often use a separate trial lens placed in front of the testing machine to give you the most accurate focus at the specific testing distance. Bifocals and reading glasses are not used directly during the test because the lens positioning matters greatly. Using the correct lens power prevents central blurring that could create false defects, so please always bring your current prescription to the appointment.
The machine tracks these responses as false-positive errors. A few are completely normal and reflect natural uncertainty when lights are very faint. However, pressing the button frequently when nothing is visible inflates the reliability error scores and can distort your sensitivity map, making results harder to interpret. If you feel yourself guessing too often, try to relax and only respond when you genuinely detect something.
Yes, and that comparison over time is actually the most important part of glaucoma monitoring. A single test tells us where you are today, but comparing multiple tests using progression analysis software reveals whether your visual field is stable, improving with treatment, or worsening. Even small consistent changes can be clinically meaningful, which is why keeping your scheduled testing appointments matters so much.
Yes. Cataracts reduce the amount of light reaching your retina and can cause a generalized dimming of sensitivity across the entire field, which may look similar to diffuse glaucoma damage. Our eye doctors account for this when interpreting your results, and we note whether cataract is likely contributing to the pattern we see. After cataract removal, visual field results often improve, which helps us reassess whether underlying glaucoma damage is present.
Not necessarily. Visual field testing is ordered based on clinical need, not at every visit. If you are healthy and low risk, your comprehensive eye exam may not include perimetry. Once glaucoma or another relevant condition is diagnosed or suspected, we will put you on a regular testing schedule tailored to how stable or active your condition appears to be. Your eye doctor will explain exactly how often you need testing and why.
Do not wait for your next scheduled visual field test. A sudden change in vision, including a new shadow, loss of part of your field, or a curtain over your sight, is a reason to contact our office the same day. Some causes of sudden vision loss are treatable if caught quickly, and delayed care can mean permanent damage. If symptoms include weakness, difficulty speaking, or facial drooping on one side, call emergency services immediately rather than calling our office first.
Schedule Your Visual Field Test at NewView Eye Center
Our experienced eye doctors are here to guide you through every step of visual field testing and to create a care plan that protects your vision for years to come. Whether you have risk factors for glaucoma, are already managing an eye condition, or simply want a thorough baseline evaluation, we are proud to serve patients across Northern Virginia with personalized, expert ophthalmology care. We invite you to schedule a comprehensive eye exam so we can discuss your needs and make sure your visual health is in the best possible hands.
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