<p>This is a STATIC, UNMOVING image but because of the placement of the colours, it looks as though it's in motion. Once you focus on one disk, it will stop.
</p>
It is called the "rotating snake" and was originally found at &lt;a href="<a rel="nofollow" class="external free" href="http://www.ritsumei.ac.jp/~akitaoka/">http://www.ritsumei.ac.jp/~akitaoka/</a>" rel="noreferrer nofollow"&gt;www.ritsumei.ac.jp/~akitaoka/&lt;/a&gt;
<a rel="nofollow" class="external text" href="https://www.flickr.com/people/43296902@N00">Dennis Sylvester Hurd</a>
CC BY 2.0
<a rel="nofollow" class="external text" href="https://www.flickr.com/photos/dennissylvesterhurd/67183712/">Optical Illusion</a>