What you’re looking for is any change from the last time you used the grid, including very subtle changes in how you see the lines of the grid. That’s why the two most important things you need to know about using the Amsler grid are these: You need to use it regularly—once a month is not enough, once a week is OK—and you have to be very consistent in how you use it. The best way to be consistent is to use the grid in the same place every time, with the same lighting conditions, and always stand the same distance from it. Without a regular weekly check and consistent use, you might miss important changes.
The second most important thing is to use the Amsler grid properly. Always test one eye at a time. As you’re doing the test, make sure you’re only looking at the dot in the center, and not moving your eyes around. As you’re looking at that dot in the center, you’re seeing whether any of the lines around it seem wavy or distorted or missing or any different than the last time you did the test.
If you’re not regular and consistent in how you do the test, or if you’re not doing it properly—one eye at a time and holding the grid still—then using an Amsler grid may just give you a false sense of security.
If you think you see a change, even a subtle one, then it’s important to call your eye care provider and get it checked out. Your doctor will likely do a dilated exam and an imaging test called an OCT, looking for any changes in your macular degeneration.
People sometimes ask, how am I going to remember to use the Amsler grid every week? The answer is, find something that you can associate it with. It could be going to church, or a TV show you watch that’s on once a week, or a magazine you get in the mail once a week. It’s really anything that is a regular occurrence or habit.