Tiéng ViêtVNTiéng ViêtVNFor most of modern history, lighting design has answered one fundamental question: Can people see clearly?
Emerging research is expanding that definition. Scientists are increasingly exploring how specific wavelengths of light interact with biological processes, suggesting that light may influence more than vision alone. One area attracting particular attention is photobiomodulation (PBM), which investigates how red and near-infrared light may affect cellular and tissue responses.
This raises an important question for the lighting industry: Could the future of lighting be about more than illumination?
Research into PBM suggests that red and near-infrared light can interact with cellular processes, particularly within mitochondria. One proposed mechanism involves cytochrome c oxidase, a mitochondrial enzyme that may act as an important photoacceptor for these wavelengths. These interactions have been associated with changes in mitochondrial activity, cellular energy metabolism, and redox signaling. [1]
However, PBM should not be confused with conventional indoor lighting. Clinical and laboratory studies typically use specific wavelengths, irradiance levels, exposure times, and delivery methods. Their findings cannot simply be translated into everyday architectural lighting.
What PBM research does demonstrate is a broader principle: light can interact with biology in ways that extend beyond its traditional role in illumination.
The relationship between red light and the eye is another area of growing scientific interest. A 2024 randomized controlled trial investigated the short-term effects of extremely low-irradiance LED photobiomodulation on retinal function in people with age-related macular degeneration. The study reported improvements in certain measures of visual function following treatment. [2]
These findings are promising, but remain preliminary. They do not establish that everyday red lighting can prevent or treat eye disease. Instead, they highlight an important research direction: the interaction between light spectrum and the eye deserves greater attention as lighting technology continues to evolve.
While red light research is opening new conversations, blue light remains central to discussions about healthy lighting. Yet the science is more nuanced than simply saying that “blue light is bad.”
Light reaching the eye plays an important role in regulating the body's circadian system. Specialized retinal cells containing melanopsin are particularly sensitive to short-wavelength light and help communicate environmental light conditions to the brain. Research shows that the effects of light depend not only on its spectral composition, but also on factors such as intensity, duration, and time of exposure. [3]
This means the question should not simply be:
“Is blue light bad and red light good?”
A more meaningful question is:
“What kind of light does the human body need—and when?”
Traditional electric lighting was designed primarily to provide consistent illumination. Human biology, however, operates on a changing daily rhythm.
Advances in LED technology and lighting controls now make it possible to create more dynamic environments that respond to different times of day. Morning and daytime lighting can provide brighter, more stimulating conditions, while evening environments can transition toward warmer and less intense light.
The goal is not necessarily to recreate natural daylight indoors, but to recognize that timing matters as much as spectrum when considering how people experience light throughout the day.
For lighting manufacturers, this represents a shift in perspective. Healthy lighting is not simply about achieving the right lux level, colour rendering, or energy efficiency. These remain essential, but the growing understanding of light and human biology suggests that spectrum, intensity, and timing should also be considered as interconnected elements of lighting design.
For NVC Lighting, this supports the continued development of human-centric lighting—creating lighting environments that respond more naturally to people's visual and biological needs.
The science is still evolving, and many questions remain unanswered. But one direction is becoming increasingly clear: the future of healthy lighting is not about finding one “perfect” wavelength. It is about delivering the right light, at the right intensity, at the right time.
[1] Hamblin, M. R. (2018). Mechanisms and Mitochondrial Redox Signaling in Photobiomodulation. Photochemistry and Photobiology, 94(2), 199–212.
[2] Franceschelli, S. et al. (2024). Short term effects of extremely low irradiance photobiomodulation on retinal function, in age related macular degeneration. European Journal of Ophthalmology.
[3] Tähkämö, L., Partonen, T., & Pesonen, A.-K. (2019). Systematic review of light exposure impact on human circadian rhythm. Chronobiology International, 36(2), 151–170.