Are you curious about how to evaluate your autonomic nervous system? Today, we’re discussing a specific clinical assessment that uses pupil dynamics to help you better understand your nervous system. In this blog, we’re going to do a vagus nerve assessment—the Samogyi reflex.
Rather watch or listen?
How Pupil Size Reflects Nervous System Activity
One clinical way to assess your autonomic nervous system is by observing pupil size and reactivity during your normal breath cycle—inhalation and exhalation.
- During inhalation, the pupils dilate slightly, reflecting a sympathetic response.
- During exhalation, the pupils constrict slightly, reflecting a parasympathetic response.
A lack of this dynamic response may indicate imbalances in autonomic nervous system regulation. However, this is just one piece of the puzzle. Comprehensive evaluation should also include a detailed history and an understanding of your unique nervous system and bio-individuality. A holistic approach ensures a deeper understanding of your nervous system function and overall health.
The Samogyi Reflex
This technique is referred to as the Samogyi reflex, describing the rhythmic fluctuation in pupil size that occurs in response to the autonomic nervous system’s interaction with the respiratory cycle.
- On inhalation, the sympathetic nervous system activates, causing pupil dilation. This is part of the fight-or-flight response, where the body prepares to respond to potential threats.
- On exhalation, the parasympathetic nervous system activates, causing pupil constriction (miosis). This reflects the rest-and-digest state, promoting relaxation and recovery.
The clinical significance of this reflex lies in its ability to serve as a marker of autonomic balance, reflecting the interplay between the sympathetic and parasympathetic branches during natural respiration.
Abnormalities and Their Implications
Abnormalities in this reflex—such as reduced or exaggerated pupil changes—may indicate autonomic dysfunction or imbalance. Potential associations include:
- Chronic stress
- Chronic fatigue
- Neurological disorders
- Postural Orthostatic Tachycardia Syndrome (POTS)
- Trauma
- Vagus nerve dysfunction
How to Perform This Vagus Nerve Assessment
You can perform this assessment on yourself:
- Observe your pupil size while inhaling and exhaling.
- Use a mirror to carefully watch for slight dilation during inhalation and slight constriction during exhalation.
It may take a few attempts to notice the changes. If the response is underactive or overactive, consider incorporating strategies such as:
- Vagus nerve stimulation
- Breathwork
- Other nervous system and somatic practices
The Bottom Line
Remember, this assessment is just one tool. It should be part of a broader evaluation of the nervous system, which is highly complex.
Next Steps
If you found this helpful, please give it a like, share it, and subscribe to our YouTube channel, the Movement Paradigm, for weekly tips on mindset, nutrition, and movement. Our goal is to help you live your best life, heal, transform, and, more importantly, thrive.
Join Our Community
You can always join us in our app, the Movement Paradigm. We have lots of challenges every other month—everything from movement to the nervous system, nutrition, and so on. And we have a great community of people.
You can also reach out to us for an individual appointment for functional medicine or holistic physical therapy. If you really want to get to the root cause, please reach out to us.
Other things that might interest you:
