Light has long surpassed the simple function of “seeing”; it is an invisible force that directly affects our body and mind. Lawrence Lin, Founder and CEO of Lighting Recipe Studio, presented cutting-edge research on light and health during a successful, in-depth special training session at Sunricher in Shenzhen, unveiling how to use “light” as a powerful remedy to create a whole new chapter of healthy living.
From “Seeing” to “Sensing”: Redefining the Value of Light
The training began by challenging conventional thinking. We explored the dual visual and non-visual pathways of human perception. Traditional lighting focuses solely on the “visual” — enabling us to see clearly. Healthy lighting, however, targets non-visual effects, directly regulating our physiological and psychological states through ipRGCs (intrinsically photosensitive retinal ganglion cells).
DLMO: Keys to Circadian Rhythm Design
1. Core Parameters
- DLMO (Dim Light Melatonin Onset): The core concept in nocturnal chronobiology, used to mark the phase of the body’s endogenous biological clock. DLMO is not only an indicator for basic research but also the cornerstone for clinical measurement of nocturnal melatonin secretion. Its accurate determination requires integrating the physiological mechanism, measurement standards, and individual application scenarios to realize the “translational value of biological medicine.
- CS (Circadian Stimulus): Quantifies the stimulus strength (0-1) to the circadian rhythm system, based on the sensitivity of “ipRGCs” to blue light.
- Duration: Integrates light intensity and the cumulative effect of the relative phase shift.
- Age Correction: Considers lens status light transmittance (17% in the elderly compared to young adults) and retinal development (high sensitivity in infants).
2. Time Segmentation (Suggested Model)
- Morning (6:00-9:00): High CS values promote circadian rhythm phase advance and alertness.
- Afternoon (12:00-16:00): Maintains a moderate CS value for recognition.
- Evening (18:00-21:00): Low CS values reduce melatonin suppression.
- Bedtime (After 21:00): Close to zero light exposure (CS < 0.05).
DLMO Model and Design Standards
Based on the DLMO (Dim Light Melatonin Onset) model developed in collaboration with Professor Lin Yandan, we proposed quantifiable standards for circadian lighting design: during the day, M-EDI should exceed 250 (or EML 275), while at night it should remain below 50 M-EDI, and after sleep onset, ideally below 10 M-EDI, creating a truly “dark environment” for the body.
Spectral Codes for Mood
Using fMRI technology, we observed how different light spectra activate the brain’s emotional centers, enabling us to create precise “light prescriptions” tailored to various scenarios, such as focused work or relaxation.
On-site Diagnostics and Interaction
Participants took part in hands-on assessments that directly addressed “suboptimal light health” conditions.
Theory Must Be Validated Through Practice
We conducted on-site demonstrations and measurements using professional devices such as In. Licht Ultra and In. Licht Well.
The common complaint — “not bright enough during the day, not dark enough at night” — was confirmed: measurements revealed that the vertical illuminance at the meeting venue was far below the CIE-recommended standard of M-EDI > 250 for daytime.
Quantifiable Healthy Spaces Through the Five Senses
We applied the WELL Building Standard and clearly demonstrated the coordinated design of the five senses: sound, light, thermal, air, and water.
Finally, we systematically summarized the fundamental differences between traditional lighting and healthy lighting, and outlined a new design logic priority sequence:
A. Based on national or international standards for safety, task performance, and energy efficiency (Safety & Visual Tasks)
B. Predefined scenarios using circadian lighting design (Circadian Support: CS, EML, M-EDI, DLMO)
C. Priority scenarios based on activity needs (Activity Adaptation: learning, work, rest)
D. Optimization scenarios for emotional lighting (Emotional Optimization: color, dynamics, personalization)
Finally, Lawrence reiterated that, from supporting infants’ visual development to ensuring restful sleep for the elderly, light should serve as a lifelong remedy for health.
With the exchange of ideas and consensus reached, the special training session concluded successfully. We sincerely thank our partners at Sunricher in Shenzhen for their professionalism and enthusiasm! We firmly believe that every renewed understanding of light is a step toward a healthier and more human-centered future.
Lighting Recipe is not just about illumination—it is a prescription for health.