For your very own astigmatic mirror, you may download the above color image, or make your own.
So now you have a picture of what looks like the iris of the eye. Place it on a window at eye height, and get back far enough so you can still make out most of the lines with your glasses/contacts off.
Okay. Look at the lines near the center. What do you notice? If you are astigmatic you will notice that some of the lines are darker in some directions than others. Get used to the wheel for a little while and experiment with it. Try tilting your head or looking at it sideways. Try looking around the inner or outer circle. Try just staring blankly past the wheel. Notice what happens in each case. Try blinking or yawning. Try palming for a minute or two. Try covering each eye with a hand quickly to see what the difference is between your eyes.
If you a "typical" astigmatic, you may see the lines near the horizontal are clearer and darker than the lines vertically. You may also find the lines near the horizontal are spaced further apart and the vertical spaced closer together. You might also find the inner circle in not quite round.
Try looking at it with your glasses on. If your glasses fully correct astigmatism, then all the lines should be the same darkness and distance apart. If your glasses do not correct the astigmatism properly than you will still see some lines darker than others.
Say you find the lines that are horizontal to be darker. Your aim is to make the vertical lines darker. So begin by removing any glasses/contacts, relaxing and taking a few deep breaths. Blinking naturaly and breathing normaly, find the line which is the faintest, and move your eye slowly and deliberatly up and down that line, imagining it to be getting darker and darker. Tell your self to relax, relax. And imagine that line to be getting darker and darker. The key is to relax your eye has much as you can. You may want to start by massaging around the eye, and maybe doing a couple of minutes of palming. With a bit of practice you will be able to make the lines in any orientation darker than the rest, but your goal is to make them all equally dark. If you are myopic its worthwhile to place your wheel on a window, as you get a lot of contrast between the black and fluoro colours of your wheel, and also you can check out the window to see what effect playing with the wheel is having on your vision. Its also very worthwhile putting one up at work and at home and whenever you get a break you can play with it and see what happens. The astigmatic mirror allows you to leverage your own visual distortion to work for your benefit.
You will need an A4 sheet of paper, a ruler, a protractor, a compass, a pencil and a 0.2mm black marker. Find the center of the paper, and using a pencil draw a circle almost as large as the paper (diameter 20cm) with the center of the circle at the center of the paper. draw another smaller circle from the same central point about radius 1cm. Then draw a line cutting the large circle in two, but not crossing over the inner small circle, ie, Leave the inner small circle blank. Then divide the two pies you have in two again. Again not drawing inside the inner circle. Now you have 4 pie shapes. Then divide each of these in two again, so you have eight wedges, and then again so you have 16 and then one final time. So you have a spoke every 10 degrees. The result looks like a bicycle wheel. Now using your marker draw over the spokes of the wheel with nice sharp dark black lines, make sure all the lines are the same darkness.