How to use an Amsler grid

Step by step

1. Wear your reading glasses. Use the glasses or contacts you normally read with.
2. Find good light. Even room light or daylight, with no glare on the grid.
3. Hold the grid 12 to 14 inches (30 to 35 cm) from your eyes. That is normal reading distance. Taping a paper grid to the wall at eye level keeps the distance steady.
4. Cover one eye with your hand, without pressing on it.
5. Look at the center dot with the open eye and keep your eye on it.
6. While looking at the dot, notice the rest of the grid. Then cover the other eye and repeat.

What to check

• Can you see all four corners and all four sides?
• Are all the lines straight and unbroken?
• Are all the squares the same size?
• Is any area blurry, dim, dark or missing?

If you notice a change, mark it. On the online test you tap the squares. On paper, draw over the area with a pencil and write the date.

How long to look

A few seconds of steady looking for each eye is enough. Staring for a long time does not make the test more sensitive. If you stare at any pattern without blinking, parts of it can seem to fade, and that is normal. Blink, look away, and look back at the dot.

Common mistakes

• Testing with both eyes open. The better eye hides problems in the other one.
• Letting the eye wander. If you look around the grid, you look at each part with the center of your vision and the damaged area moves with you. Keep looking at the dot.
• No reading glasses. Blur from the wrong focus hides fine changes.
• Changing the distance. A grid held closer or farther covers a different area, so results cannot be compared.
• The wrong size. A grid shrunk by the printer or shown on an unset screen is not the real test. Measure a printed grid, and on a screen set the screen size.

Bifocals and progressive lenses

With bifocals, look through the reading part at the bottom. Progressive lenses can bend straight lines near the edges of the lens, which can look like a problem with your eye. If you have single-vision reading glasses, use those. If you only have progressives, keep your head still and point your nose at the dot.

If you cannot see the center dot

Use a grid with diagonal lines and look at the place where they would cross. Then tell your eye doctor that the dot was not visible, because that is itself a finding.

What to do with the result

Anything new or changed: call your eye doctor right away. See what the results mean.