Developed by the Tibetan Monks to improve the fitness of their eyes, this chart goes back centuries.  Use the chart by placing your nose at the center as close as it is comfortable for you, then just follow the triangular shapes out to the circles in each direction.  Do this slowly, taking care not to strain your eyes.

As you get better at it move in closer and try different things, like letting your eyes follow all the circles until you come back to the start.

Make up your own exercises and share them with the rest of us.