Amsler grid [Marc Amsler, Swiss ophthalmologist, 1891–1968] , a checkerboard grid of intersecting dark horizontal and vertical lines with one dark spot in the middle. To discover a visual field defect, the person simply covers or closes one eye and looks at the spot with the other. A visual field defect is perceived as a defect, distortion, blank, or other fault in the grid. The person may record the defects directly on a paper copy of the grid that may be kept as a permanent record. The Amsler grid is used in testing for macular degeneration. See age-related macular degeneration.
