This morning I happened to read an excerpt of a poem that described someone has having eyes that were “stiffened” in horror. “Stiff eyes”—what a striking description. And it got me thinking about the connection between stiff eye muscles and stiff necks.

To feel what I’m talking about, try this experiment. Lightly place your finger pads along the back of your neck, just below your hairline. Then imagine a fly buzzing around in front of your face. Follow the fly with your eyes, but without moving your head around…