Amsler Grid Test

What this test screens for and who it helps

The Amsler Grid Test is a quick screening tool that helps you check for changes in your central vision. It is often used to monitor for visual distortions or blank spots that can occur with macular conditions, such as age-related macular degeneration (AMD), diabetic macular edema, macular hole, or epiretinal membrane. The test will not diagnose any condition, but it can alert you to changes that should be evaluated by an eye doctor.

This test can be useful for adults who notice that straight lines look wavy, text seems distorted, or there is a gray or dark area near the center of vision. It is also commonly recommended by eye care professionals for people who have risk factors for macular disease—such as being over age 50, having a family history of AMD, or living with diabetes—or for those already under care for a macular condition.

Please remember: online screening tools are not a substitute for regular, comprehensive eye exams with an optometrist or ophthalmologist.

How to take the test correctly

Before you begin

• Lighting: Use bright, even room lighting to avoid glare or deep shadows on your screen or paper.
• Screen and brightness: Set your screen brightness to a comfortable, medium level. Turn off “night mode”/blue light filters during the test so contrast stays high.
• Distance: Sit at your normal reading distance—about 14–16 inches (35–40 cm)—from the screen or printed grid. Keep the grid at eye level.
• Wear your usual near correction: If you use reading glasses, bifocals, progressives, or multifocal contacts, wear them. Contact lens wearers should keep lenses in. If you only wear glasses for distance, you may not need them for this near test.
• Consistency: Try to use the same device, settings, and distance each time so you can compare results over time. If you have a printed grid, use a clear, high-contrast printout.

During the test

• Cover one eye gently without pressing on the eyelid. Test one eye at a time.
• With the uncovered eye, focus on the small dot in the center of the grid. Keep your gaze on the dot the entire time.
• While looking at the dot, notice whether the grid lines look straight and evenly spaced, and whether you can see all four corners of the grid without moving your eyes.
• Blink normally. Observe for 15–30 seconds.
• Repeat the process with the other eye.

After the test

• If anything looks wavy, missing, blurred, darker, or distorted, note where you see it. If using a printed grid, you can lightly mark the area. On a screen, consider taking a screenshot and describing the location.
• If you are unsure, rest your eyes, adjust lighting, and repeat the test once. If the same change appears again, consider it significant.

How to read your results

A result that appears typical is when all lines look straight, parallel, and evenly spaced; the squares are uniform; the center dot is visible; and you can see the entire grid while keeping your gaze on the center. Each eye should be tested and compared separately.

A result that suggests a possible change is when any of the following are present in one or both eyes while you keep your gaze on the center dot:

• Lines that appear wavy, bent, or warped
• Squares that look stretched, shrunken, or uneven
• Areas that look blurred, gray, dark, or “missing”
• Difficulty seeing the center dot or the edges of the grid without moving your eyes

If you notice a new or worsening change, especially if it is different between eyes or different from your past results, save a record of what you saw and contact an eye care professional.

What to do if your result is poor

First, do not panic. Glare, dry eyes, fatigue, or screen settings can sometimes affect what you see. Blink, adjust the lighting, ensure you are at your normal reading distance, and repeat the test. If the distortion, missing area, or blur persists, it is important to book a comprehensive, dilated eye exam with an optometrist or ophthalmologist.

• Timing: If you notice new central distortion, a new dark or missing area, or a sudden drop in central clarity, contact your eye doctor as soon as you can to arrange an evaluation.
• If you are already being followed for a macular condition: Notify your eye care team about the change and follow their guidance. Bring your marked grid or a screenshot to your appointment.
• Urgent symptoms: If you experience sudden vision loss, a curtain or shadow in your vision, or many new floaters with flashes of light, seek urgent or emergency eye care.
• Safety: If your central vision is significantly affected, use extra caution with activities such as driving or operating machinery until you are examined.

Only an in-person, comprehensive exam can determine the cause of abnormal Amsler results and whether treatment is needed.

Limitations of online tests

Online Amsler grids are helpful for screening and self-monitoring, but they have important limitations:

• Device variability: Screen size, pixel density, contrast settings, viewing angle, and anti-aliasing can change how lines appear. Printing quality can also vary.
• Scaling and distance: If the grid is too small or too large, or if viewing distance changes, subtle changes may be harder to notice. Using the same setup each time helps consistency but does not guarantee accuracy.
• Eye surface and lighting factors: Dry eye, glare, or fatigue can alter what you see temporarily.
• Not a diagnosis: A normal Amsler result does not rule out macular disease, and an abnormal result does not identify the cause. Only a comprehensive, dilated eye examination can evaluate the macula and the rest of the eye.
• Scope: This test checks central vision only. It does not assess peripheral vision, eye pressure, cataracts, or overall retinal health.

Organizations such as the American Academy of Ophthalmology and the National Eye Institute note that home monitoring tools can complement, but never replace, regular professional eye care.

Disclaimer: This online Amsler Grid Test is a screening aid only. It does not diagnose any condition and does not replace a comprehensive eye examination by a licensed eye care professional.