Your Vision and Pain

As I’m working through the S-Phase material with Z-Health, I’m learning more about neuroanatomy, and the ways in which we can use our knowledge of neuroanatomy to help people move and feel better. The most recent “aha” moment for me was learning about an area in the brainstem called the periaquaductal gray (PAG).

The PAG is located in a part of the brainstem called the mesencephalon, and we have an anti-nociceptive pathway that begins in the PAG. This anti-nociceptive pathway plays a large role in diminishing our pain experience, which means that if we increase activation of and around the PAG, we are more likely to reduce pain. One of the cranial nerves, CNIII (oculomotor), that controls many of our visual functions has a nucleus very close to the PAG. Because activation of neighboring neurons increases activation in a given area, we can potentially increase activation of the PAG (and therefore decrease pain) by activating CNIII.

So what does this mean practically? Cranial nerve III is responsible for many things, including:

• Accommodation (the ability for the lens to switch between seeing near and seeing far)

• Pupillary reflex (the ability of our pupil to dilate and constrict)

• Eye movements (particularly in, up, down, in & up, out & up)

By doing visual exercises that target these particular visual skills, you will be increasing activation of the PAG and potentially decreasing your pain experience — pretty cool! Here are some things to try:

• Switch back and forth between focusing on something near and something far (at least 40 feet away if possible)

• Use the flashlight on your phone to provide extra light input in your periphery (meaning, don’t shine it straight into your eyes!), and do this in waves (5 seconds on, 5 seconds off, for example) to trigger the pupillary reflex

• Move an object up and down in a vertical motion, following with your eyes and keeping your head still

Let me know what you discover!