The Amsler grid is a simple at-home exam people can use to detect or monitor age-related macular degeneration (AMD) and other eye problems. AMD is a common condition that causes vision loss in older people.

The Amsler grid is a square-shaped grid with a dot in the middle. With daily use, people may notice subtle changes in their vision that indicate the development of AMD or worsening symptoms. Changes may also indicate other eye problems. Eye doctors will then carry out further tests to confirm the diagnosis.

This article explains what the Amsler grid is and how to use it. It also highlights warning signs to look for that may indicate other vision problems.

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Illustration by Alyssa Kiefer

The Amsler grid eye exam is a simple yet effective way for people to monitor changes in their vision daily. The grid is a square of intersecting horizontal and vertical lines. These lines form squares, and the Amsler grid consists of 20 rows and 20 columns of small squares. The grid measures roughly 4 inches (in) or 10 centimeters (cm).

To monitor their vision, a person focuses on a small dot in the center of the grid. The idea is that the person can see the entire grid while looking at this spot. Closing one eye, the person holds the grid about 13 in (33 cm) away from their eyes and focuses on the dot.

According to the National Eye Institute, the risk of developing AMD increases with age. People ages 55 and over are at a higher risk, especially if they have a family history of the disease. The risk is also higher among white people and people who smoke. Individuals in these groups can benefit from the Amsler grid exam.

The Amsler grid exam is one of the tests doctors perform before diagnosing AMD or another eye condition. Anyone noticing visual changes during the exam must tell their optometrist or ophthalmologist and arrange a thorough eye exam.

Learn more about AMD.

People taking the Amsler grid exam should look out for any changes they see to the lines and squares. Some people find the squares blurry, there may be patches where squares are missing, or parts of the grid may appear darker than others.

Some people see wavy lines instead of straight ones, or the lines may appear distorted. Doctors also ask people to check that they can see all four corners of the grid.

Changes in vision can be gradual, and many people only notice them once they are quite pronounced. The macula is the part of the retina that lets people see details clearly and gives them central vision. It helps people recognize faces and read text.

People with AMD may notice that their central vision is blurred or have difficulty seeing when light levels are low. Other visual changes to look out for include:

  • blank spots in central vision
  • difficulty reading a clock face
  • difficulty threading needles
  • seeing straight lines, such as countertops or door frames, as wavy or wobbly
  • difficulty doing close-up work
  • colors appearing muted

Learn about some potential signs of AMD.

The Amsler grid is easy to use at home. Experts recommend taking the exam in good lighting, ensuring people can see the entire grid. Those who usually wear glasses or contact lenses should wear their near-correction types for the exam.

  1. Position the grid about 13 in (33 cm) in front of the eyes.
  2. Cover one eye, then focus on the dot in the center of the grid.
  3. Without moving the head or eyes, notice what the grid looks like.
  4. Make a note of any visible irregularities. Some people mark their grids to highlight the areas of distortion, while others prefer to note things as a list.
  5. Repeat the test for the other eye. Use a new grid if the first has markings on it.

It is essential to cover one eye while using the Amsler grid. Otherwise, vision problems may not be apparent.

Read about how doctors test for AMD.

The Amsler grid exam is a simple sight test people can do at home. It involves closing one eye, looking at a printed grid of squares, and noticing any distortions.

People with eye conditions, such as AMD, who perform the Amsler grid exam daily may be able to detect any abnormalities at an early stage and arrange for a thorough eye exam.

While there is currently no cure for AMD, doctors can slow its progression and help preserve a person’s vision.

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