In Part I, we reviewed an article cited by LRS’s U.S. partner LEDmetric:
“The Light Revolution: Top Three 2026 Light Studies That Change Everything.”
Based on three categories of studies, the article presented relatively aggressive, highly communicative conclusions:
- High ultraviolet exposure is associated with lower mortality
- LED environments lacking near-infrared may affect mitochondria
- Natural light may help stabilize blood glucose
On social media, these findings were further amplified into simplified messages:
- “LED may be harmful”
- “We should return to full-spectrum light sources”
In the first two parts of this trilogy, we established three core models: dose, spatial, and human factors.
This final part addresses two key questions:
What does the scientific system actually support?
And how should the industry rationally upgrade its development path?
I. Social Media Narratives vs. the Scientific System
1️⃣ CIE S 026 Does Not Define a “Healthy Light Source”
CIE S 026 provides:
- A weighted calculation framework for five photoreceptors.
It does not:
- Recommend any specific light source
- Reject LEDs
- Promote incandescent lamps
It does only one thing:
- Provide a calculable spectral weighting method.
In other words:
Science provides evaluation tools, not emotionally driven conclusions.
2️⃣ The Real Meaning of Melatonin Suppression Research
Classic studies (e.g., Lucas et al., Brown et al.) show that:
- Melatonin suppression correlates with melanopic stimulus intensity.
But their core findings are that:
- There is a dose–response relationship
- There is time dependence
- There are individual differences
They do not conclude that:
- “Any particular light source is inherently harmful.”
3️⃣ IEEE 1789 and the Flicker Issue
Flicker risk assessment provides guidance on neurological safety.
Its focus is on:
- Waveform modulation
- Frequency ranges
—not on the type of light source itself.
4️⃣ The Position of the WELL Light Concept
WELL emphasizes:
- Daytime circadian support
- Nighttime circadian protection
- Vertical illuminance
- Equivalent Melanopic Lux
But it does not advocate a return to incandescent lighting.
What it emphasizes is:
- Verifiable light exposure structures.
II. Should We “Return to Incandescent Lamps”?
We must be clear:
We do not support a simple return to incandescent lighting.
Reasons include:
1️⃣ Energy efficiency and carbon emissions
2️⃣ Insufficient spectral controllability
3️⃣ Limited dynamic adjustability
4️⃣ Incompatibility with modern smart building systems
The advantage of natural light lies not in “light source technology,” but in:
- Dynamic structure
- Continuous spectrum
- Temporal variation
Industry upgrading should not mean technological regression, but rather technological integration.
III. The Real Path Forward: Multi-Band Semiconductor Integration
The future is not:
- “LED vs. incandescent,”
but rather:
- Controllable, multi-band semiconductor integrated systems.
Including:
- Optimized full visible-spectrum coverage
- Precise regulation of melanopic ratios
- Integration of near-infrared (NIR) bands
- Dynamic temporal control
- Integration with control systems
NIR has been amplified in recent research discussions.
However, it must be emphasized:
If NIR is introduced, we must answer:
- What is the appropriate dose range?
- How are long-term exposure thresholds defined?
- Are there tissue-level differences?
- Do we have measurement and verification methods?
All of this must be built on a rigorous engineering framework.
IV. Causation vs. Correlation: The Boundary of Industry Communication
In discussions of healthy lighting, it is essential to distinguish between:
- Epidemiological correlations
- Short-term intervention studies
- Mechanistic basic research
- Long-term causal validation
Industry communication must avoid claims such as:
- “A certain spectrum cures disease”
- “A certain light source is inherently harmful”
The correct framing should be:
Under specific dose and temporal structures,
certain spectral combinations may support particular physiological pathways.
This is not only a matter of scientific rigor, but also of industry responsibility.
V. LRS’s Scientific Expression Framework
In building the light exposure management ecosystem, we consistently adhere to four principles:
1️⃣ Biological plausibility
– Alignment with established physiological research
2️⃣ Clear dose boundaries
– Defined intensity and time ranges
3️⃣ Spatial feasibility
– Achievable through engineering implementation
4️⃣ Long-term verifiability and repeatability
– Measurable and re-measurable
This framework is why we reject “slogan-based upgrades.”
The positioning of the In. Licht device series and algorithm platform was formed within this framework:
- Not to claim “healthier” lighting,
- But to provide measurable, verifiable, and repeatable exposure-management tools.
VI. The Direction of Industry Ecosystem Upgrading
The future industry structure will likely take the form of a three-layer architecture:
Layer 1
Embedded spectral sensing nodes (integrated with control systems)
Layer 2
Verification-grade reference instruments (full visible-spectrum coverage, expandable to NIR)
Layer 3
Professional analytical software platforms (supporting research, design, and WELL projects)
This is not merely a device upgrade, but an ecosystem upgrade.
VII. Conclusion: What Is the Real “Light Revolution”?
The true revolution is not a return to the past, but:
- From “light source debates” to “light exposure management”
- From “parameter stacking” to “structural models”
- From “emotional narratives” to “verifiable ecosystems”
Only when the industry possesses:
- Structured models
- Standard-alignment capability
- Multi-band integration technologies
- Measurement and re-measurement mechanisms
will discussions of light and health truly mature.
Complete Series
Light Exposure Management Trilogy
- Part I: Research Hype and Rational Frameworks
- Part II: Dose–Space–Human Models
- Part III: Scientific Benchmarks and Industry Pathways
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