This interactive Java applet shows the tracking principles. You can control the target (white disk) with the mouse. The applet will try to track the moving target by moving the saccade (the circle initially constituted of grey circles) using the same algorithm that is implemented on the real system.

Please note that the speed is not related to the tracking speed that can be obtained with the real system. Moreover, the tracking speed depends on your internet connection.

What you can do to interact with the applet (click at least once on the applet window in order to activate it):
- Move the target with the mouse in the same way as a cursor.
- Change the target radius size (with keys 'w' and 's').
- Change the number of points that constitutes the saccade (with keys 'q' and 'a').
- Choose to display the trajectories of both the saccade and the target (toggle with the key 't').

Play with the target, change the radius or the number of points and observe the result !