I have had some things happen like that, too...especially when I am cutting out fabric that is any shade of red, against the backdrop of my green cutting mat. Since they are opposites on the color wheel, I know that is not unusual. At my quilt group today we were just discussing this topic. One of the ladies was choosing a backing fabric for a quilt, the colors in the fabric were red, black, white, and yellow print...it seemed to do the "pulsate and jump" trick, too...she did buy some of it, but is going to do a pieced backing so she can "break up" some of the dizzying pattern. I also know that eye fatigue can really play tricks with one's eyes.
Take care all,
Kif