The document describes the Amsler grid chart, which was developed in 1920 by Dr. Marc Amsler to test for central vision disorders. It consists of a grid pattern with white lines on a black background that is used to evaluate the macula. Patients are asked a series of questions while viewing the chart to check for blurriness, distortions, or missing areas that could indicate conditions like macular degeneration or retinal detachment. The document outlines the purposes and procedures for several variations of the Amsler grid and provides instructions for patients to perform self-examinations at home in order to monitor eye conditions.