Human-Centric Lighting Was Focus of Seoul Semiconductor Symposium

South Korean LED technology company Seoul Semiconductor, hosted a half-day symposium about scientifically and objectively demonstrating the effects of light on health and circadian rhythm. The symposium, which featured academics and industry insiders, was held on March 21 in conjunction with Light + Building 2018. The tile of Seoul Semiconductor’s symposium was “Human-Centric Lighting & Health.”

Human-Centric Lighting Improves Health and Well-being

Human-centric lighting is the use of artificial lighting to improve the health and well being of those who use it. One of the ways of doing this is through creating light with a spectral distribution that is as close to that of natural sunlight. Seoul Semiconductor accomplished this with the development of its SunLike Series LEDs. The company put on a symposium to discuss the latest research in academia about the effect of lighting on circadian rhythms and health.

Seoul Semiconductor also highlighted how its SunLike Series LEDs with a spectral distribution like natural sunlight, can help people maintain healthy sleep patterns and circadian rhythms. The company further emphasized how the SunLike Series LEDs make an ideal light source for human-centric lighting.

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The symposium consisted of presentations from several invited experts, including Professor Russell Foster from the University of Oxford, Dr. Manuel Spitschan from the University of Oxford, and Dr. Octavio L. Perez from Mount Sinai Hospital in New York.
Professor Foster is a leading authority in light, sleep, and circadian rhythm research. All three experts delivered presentations about the effects of light on human health, and they discussed the future of lighting.

Light Plays Critical Role in Our Perception of Time

According to Professor Foster, “Light not only allows us to perceive space, but also plays a critical role in enabling us to perceive time by controlling our circadian rhythm and sleep.

Seoul Semiconductor Symposium on Human-centric Lighting--Dr. Russel Foster gives lecture about light, sleep, and circadian rhythm.

Seoul Semiconductor Symposium on Human-centric Lighting–Dr. Russel Foster gives lecture about light, sleep, and circadian rhythm.

Professor Foster indicated, however, that many artificial lights disrupt circadian rhythms. “To sustain a healthy and happy life, we must get the best sleep and keep our circadian rhythm at an optimum level. We also need to replace today’s artificial lighting systems that hinder our circadian rhythm with more human-centric lighting,” he said.

During another presentation, Dr. Manuel Spitschan from the University of Oxford stressed the influence of light on the body’s circadian rhythm, stating, “Light has an extremely significant impact on human eyes and brain, due to the photoreceptors in the retina. These receptors perceive red, green, and blue light, and accept the color spectrum in varying degrees.”

Blue Light Inhibits the Production of Melatonin

Dr. Spitschan explained how the human brain responds to blue light, “In particular, intrinsically photosensitive retinal ganglion cells (ipRGC), deliver signals from light via a direct connection to the brain, and react more sensitively to blue light within a certain wavelength. When these cells are activated, it causes the body to inhibit the production of melatonin, a hormone that regulates sleep, therefore affecting the 24-hour circadian rhythm.”

Discussing the importance of sunlight in next-generation architecture standards, Dr. Octavio Perez from Mount Sinai Hospital in New York explained, “Typically, people who live in buildings with great lighting – in other words, buildings that get a lot of sunlight – are healthier and happier, compared to people living in artificially-lit indoor spaces. This is because artificial light features a spectrum that vastly differs from natural sunlight.”

Artificial Lights Such as Fluorescents and LEDs Hinder Circadian Rhythms

“Artificial light, such as fluorescent light and LEDs that emit a spectrum with irregular light waves, hinder the user’s circadian rhythm and eyesight,” Dr. Perez continued. “In the long term, this exposure to artificial light is known to have a negative impact on the human body.”

Dr. Perez described how the light from Seoul Semiconductor’s SunLike Series of LEDs is different saying, “… the SunLike Series natural spectrum LEDs create light with a spectrum that is close to sunlight, offering significant benefits for eye protection and accurate color reproduction.”

The SunLike Series LEDs utilize Tri-R phosphor technology developed by Toshiba to produce white light with spectrum distribution that closely mimics natural sunlight.

Dr. Perez also stated, “Development in light fixtures which use natural light sources such as SunLike Series LEDs, will revolutionize future standards and design, as the construction industry applies even stricter standards to provide people with good quality light. As such, companies must focus on developing light fixtures that produce natural light.”

Seoul Semiconductor noted that SunLike natural spectrum LED technology, that Seoul Semiconductor and Toshiba Materials developed, was awarded the Gold Award by Elektronik (, a German magazine specializing in electronic components with a large number of German subscribers.

Won continued, “This Symposium presented scientific, objective evidence on the impact of light on our circadian rhythm, sleep, and health.”

“The SunLike Series LEDs, which recreate light that closely matches the natural spectrum of sunlight, promises to be the next-generation light source to lead the era of human-centric lighting,” Won concluded.