The French Impressionist painter Edgar Degas had progressive visual loss from a type of maculopathy during the last 40 years of his life. The effects of this visual failure are evident in a comparison of early and later pastels, which shows a loss of precision in outlining, shading, and detail over the years. A remarkable oil painting, Scene from the Steeplechase: The Fallen Jockey, provides on one canvas an historical record of his visual struggles. It was begun in 1866 and reworked in 1880 and 1897, during which his visual acuity fell from near normal to 20/200. Computer simulations show Degas’ own view of this painting at each of these times and demonstrate how his style changed: details became rougher and larger in correspondence with his failing acuity. The painting is an eye chart of his career.