Visual Field Testing in Palamu
Comprehensive perimetry (visual field testing) for glaucoma, neurological vision disorders, and optic nerve conditions — performed and interpreted by Dr. Dibya Prabha at Palamu Neuro & Eye Care.
What is Visual Field Testing (Perimetry)?
Visual Field Testing (Perimetry) is a specialized diagnostic exam that precisely maps your entire field of vision, including your central and peripheral (side) sight. By asking you to respond to small flashes of light of varying intensities, the machine identifies exactly where your vision is intact and where you have 'blind spots' (scotomas). This testing is available at Palamu Neuro & Eye Care and is crucial for detecting diseases that slowly steal side vision.
Why is Visual Field Testing (Perimetry) Done?
- •To detect the subtle, early loss of peripheral vision that is the hallmark of Glaucoma
- •To map the specific visual field defects caused by neurological issues like a stroke or brain tumor
- •To evaluate the visual impact of an inflamed or compressed optic nerve (optic neuritis)
- •To monitor whether a known eye or brain condition is worsening over time or stabilizing with treatment
How Visual Field Testing (Perimetry) is Performed
- 1
Setup
You sit comfortably at the perimeter machine. One eye is patched. Your chin and forehead are positioned against supports. The room lighting is standardized.
- 2
Instructions
The technician explains the procedure: keep looking at the central orange fixation light at all times. Small white lights will flash at various locations and brightness levels throughout your visual field.
- Press the button each time you see a light — even if it's very dim
- It's normal to miss some lights — the machine is testing your threshold
- Don't look around for lights — keep your eyes fixed on the central target
- 3
Testing
The automated program presents lights at various locations in your visual field. You respond to each light you see. The machine adjusts light intensity to determine the threshold of visibility at each point. A typical test takes 5–10 minutes per eye.
- 4
Analysis
The machine generates detailed maps and statistical analyses including mean deviation, pattern standard deviation, and glaucoma hemifield test. Dr. Dibya Prabha reviews the results, compares them to any previous tests, and integrates the findings with your complete eye examination and OCT results.
How to Prepare
- •No special preparation is needed — you can eat, drink, and take medications normally
- •Bring your current glasses — you'll wear them during the test if needed (near correction for the central target)
- •Get a good night's sleep — fatigue affects concentration and test reliability
- •The test requires concentration — if you're not feeling well, consider rescheduling
- •A practice test may be run first to familiarize you with the process
Related Conditions
Visual Field Testing (Perimetry) helps diagnose and monitor these conditions. Explore our condition pages for more detailed information about each.
Frequently Asked Questions
What is a visual field test?
A visual field test (perimetry) measures your entire scope of vision — both central and peripheral (side) vision. It maps areas of vision loss (scotomas) that you may not have noticed. It is essential for diagnosing and monitoring glaucoma, neurological conditions affecting vision, and certain retinal diseases.
How is a visual field test performed?
You sit at the perimeter machine and look at a central fixation point. Small lights of varying brightness appear in different areas of your peripheral vision. You press a button each time you see a light. The machine maps which areas you can and cannot see, creating a detailed map of your visual field.
How long does visual field testing take?
A standard visual field test takes about 5–10 minutes per eye. More detailed or specialized testing may take 15 minutes per eye. It requires concentration and cooperation — the technician will guide you through the process.