Fear based thoughts = Sympathetic Nervous System
In the sympathetic state it may help you to slow down to return to the present moment and notice things around you as this will down-regulate your nervous system. This engages the vagus nerve, but also the Oculomotor nerve. This nerve helps to constrict the pupil, which makes it appear smaller. When we are in Fight or Flight our pupils dilate. So, tracking means very slowly turning to look and see what is in your environment. Then you can slowly turn your head to the side with it.