When I was in kindergarten, my teacher used to warn us that she had "eyes in the back of her head." Considering how many times she knew just which student was misbehaving, we all came to believe this was truth.
At age 43, I'm no longer convinced this was the case. However, the eyes and the back of the head have a definite connection. Take your fingers tips and place them on your occipital ridge (at the top of the neck just beneath the skull). Touch only lightly. With the head still, move your eyes up, down, right, left, and in circles. See if you can feel a subtle movement beneath your fingers. Now stare intently at an object and notice the level of tension under your fingers and around your face. Soften your gaze and widen the peripheral vision. Notice what happens to the tension at the top of the neck and face area.
Throughout the day, watch your eyes and pay attention to how frequently it's piercing and realize this impacts not only your eyes, but your muscles in the face and neck as well.
Also, when the eyes are tight, the breath moves up into the chest and becomes shallow. As the eyes relax, so does the chest allowing the breath to deepen down to the belly.