This consists of vertical 'wavy' lines overlayed with serveral parallel horizontal lines. The vertical lines should appear as three dimensional waves. The depth of the waves may be accentuated if you tilt your head to the side slightly. Click on the image to start the animation.

With movement the parallel lines appear tilted or bent by waves, and seem to follow the surface along the peaks and troughs of the waves.

When the movement stops the parallel lines fade away to leave a view of the waves alone. The Zöllner illusion is visible in these alone, that is the waves seem to diverge or converge according to the orientation of the lines that define them.

Click on the image again to view the horizontal parallel lines alone, you can hold a ruler to the screen to check they're straight and parallel. A further click will take you back to the start again.

(Note: If you don't have the Adobe Flash plugin installed clicking on the image will switch between two animations, one with the vertical movement, one alternating between the plain waves and plain horizontal lines.)