What is an Amsler grid?
A simple square grid that lets you check the center of your vision at home, one eye at a time.
Updated November 13, 2026 · General information, not medical advice.
What it is
An Amsler grid is a square of evenly spaced straight lines with a dot in the middle. The standard grid is 10 cm on each side and has 400 squares of 5 mm. You look at the dot with one eye and notice whether the lines around it look straight and complete.
It is named after Marc Amsler, the Swiss eye doctor who published it in 1947. Eye doctors have handed it to patients ever since, because it needs no equipment and takes a minute.
What the Amsler grid tests for
The grid tests the macula, the small central part of the retina that gives you sharp, detailed vision. When the macula is healthy, the grid looks regular. When part of the macula is swollen, lifted, scarred or damaged, the grid can look different in that spot:
- lines look wavy or bent;
- squares look smaller or larger than the others;
- an area looks blurry, dim or dark;
- part of the grid is missing.
See pictures of each in the distortion examples.
What the Amsler grid is used for
Its main use is home monitoring. People who have a condition that can damage the macula check the grid regularly so that a change is noticed in days, not at the next appointment months away. Eye doctors also use it during exams to map where a patient sees distortion.
Conditions it helps to monitor include:
- age-related macular degeneration, especially watching for dry turning into wet;
- diabetic macular edema;
- macular pucker (epiretinal membrane) and macular hole;
- central serous retinopathy;
- swelling of the macula after a retinal vein blockage or eye surgery.
Who should use one
Anyone whose eye doctor has recommended it. That usually means people with macular degeneration in one or both eyes, and people with the other conditions above. Some organizations also suggest that everyone over 50 check from time to time. It costs nothing and does no harm, as long as a normal grid does not replace your eye exams.
What it cannot do
The grid cannot diagnose anything, and it misses some disease. It checks only the central 20 degrees of vision, so it says nothing about side vision or eye pressure. Read more in how accurate is the Amsler grid?
Ready to try it? Take the test on this screen or print a grid.