I found this article, and the visual (below) from the American Institute of physics, fascinating.
Click here to see the illusion in action
Inside Science News Service
May 13, 2009
WASHINGTON, D.C. (ISNS) -- The three best visual illusions in the world were chosen at a gathering last weekend of neuroscientists and psychologists at the Naples Philharmonic Center for the Arts in Florida.
The winning entry, from a Bucknell University professor, may help explain why curve balls in baseball are so tricky to hit.
A properly thrown curve ball spins in a way that makes the air on one side move faster than on the other. This causes the ball to move along a gradual curve. From the point of view of a batter standing on home plate, though, curve balls seem to "break," or move suddenly in a new direction.
This year's winning illusion, created by Arthur Shapiro of Bucknell University in Pennsylvania, may explain this phenomena. His animation shows a spinning ball that, when watched directly, moves in a straight line. When seen out of the corner of the eye, however, the spin of the ball fools the brain into thinking that the ball is curving.
So as a baseball flies towards home plate, the moment when it passes from central to peripheral vision could exaggerate the movement of the ball, causing its gradual curve to be seen as a sudden jerk.
I hope the Mets know it's only an illusion!