You should wear your reading glasses (if you use these), cover your left eye and view the grid at your usual reading distance. Stare directly at the center dot with your right eye for a few seconds. Repeat this for your other eye. If any lines appear missing or crooked/wavy, or if dark spots are visible on the grid, this could be a sign of a problem. You do not need to look at the grid more than once per day, and don’t need to stare at it for more than 5-10 seconds with each eye. The grid is most useful if looked at once each day, to compare the appearance of the grid day-to-day. If there is a sudden change in the appearance of the grid from one day to the next, call your retinal specialist or eye doctor right away.