“Do you want me to do calorics or doll’s eyes?” Trey asked, referring to two methods of making the eyes move from one side to the other, thereby testing the integrity of the pons, the middle part of the brain stem. Because the patient had a collar on, and might have a broken neck, we couldn’t move his head from side to side, so we did the caloric reflex: squirting ice water into one ear, then the other. This provides a potent stimulus to eye movements through a hardwired circuit in the brainstem, if it’s functioning at all.
