If you have astigmatism then the axis will show up as distortion in one or several of the rays of the Astigmatic Mirror above. The angle of the major distortion is indicated on the chart.
People with natural clear vision see all the lines in the same thickness and exactly the same spacing between the lines.
Look at the Astigmatism chart from several distances and notice where the distortion begin and ends. It is possible to have astigmatism only at the near, or only at the distance, or at any plane in between.
Download the Acrobat file and print a chart in with the background colour you like the best. Set your printer to the highest print quality as possible.
The Astigmatic Mirror provide an accurate feedback concerning your astigmatism.
Source:http://www.vision-training.com/Vision%20test/Astigmatism%20test.htm