Seoul SunLike LEDs ease eye strain and improves sleep patterns, research confirms

Seoul SunLike LEDs ease eye strain and improve sleep patterns, two research studies discover

The positive health effects of the uniform spectral power distribution and natural light spectrum of the SunLike LEDs from Seoul Semiconductor have been confirmed in two independent studies, by universities from Switzerland and South Korea.

The new SunLike technology brings a major improvement to the LED spectral power distribution (SPD) which now mimics the SPD of the sun within the bounds of the human visual range. The SunLike LEDs use a three-phosphor mix and a violet emitter to achieve the SPD. Seoul has said that the LEDs can be used in a variety of applications including in human-centric lighting or lighting for health and well-being where tunable lighting can be applied to improve human well-being.


SunLike LED Desgin 




A study published by the University of Basel in Switzerland titled “Effect of daylight LED on visual comfort, melatonin, mood, waking performance, and sleep” found that volunteers had better visual comfort, more alertness, and happier moods associated with exposure to SunLike LEDs compared to other LEDs. 

The university published the research in the Journal of Lighting and Research Technology. Professor Christian Cajochen led the research team investigating what they referred to as LEDs with a daylight spectrum.

The results are based on a study of volunteers who, in two separate test sessions, were exposed to Seoul Semiconductor SunLike LEDs in one session and to conventional white LEDs at the same CCT in the other session. The volunteers exposed to the uniform spectral power distribution (SPD) of the SunLike LEDs experience better sleep patterns and reported improved visual comfort and heightened daytime alertness.

Seoul SunLike LEDs ease eye strain and improve sleep patterns, two research studies suggest


15 young male volunteers took part in the tests in Basel, spending 49 hours twice in a laboratory. During each session, the volunteers received light exposure at the same CCT and intensity levels, the only difference being the SPD of LED-based lighting products. 

In general, the researchers said that volunteers reported better visual comfort, more vigilance, and happier moods associated with SunLike exposure compared to conventional LED exposure. But the paper also provides some quantitative data on sleep patterns. “We have evidence that a daylight LED solution has beneficial effects on visual comfort, daytime alertness, and sleep intensity in healthy volunteers. Delta EEG activity (0.75–4.5 Hz) was significantly higher after daylight-LED than conventional-LED exposure during the post-light exposure night.” Delta EEG (electroencephalogram) tests record the brain waves associated with Stage 3 non-rapid eye movement sleep, sometimes called slow-wave sleep, that is considered indicative of the depth of sleep.

A similar result is found also in the study from the Biomedical Information Laboratory at the Seoul National University College of Medicine in Korea. There the research was conducted on adults using desk lamps based on Seoul Semiconductor SunLike LEDs and also found that the LEDs resulted in decreased eye discomfort and better sleep patterns.

The Laboratory conducted the research that had volunteers including graduate students at the university use both standard LED desk lamps and SunLike-based lamps for three hours before bedtimes. The researchers analyzed the volunteers’ vital signs during sleep and conducted subjective analysis via a questionnaire. Based on monitoring the vital signs, the team said volunteers using the SunLike lamps fell asleep 23% faster than those using standard LED lamps. And the questionnaire revealed that those using the SunLike lamps noted a decrease in eye fatigue along with improved sleep quality. 

“We conclude that these effects are due to the stabilization of the autonomic nervous system rhythm, which is manifested by inactivation of sympathetic nerve and activity of parasympathetic nerve by SunLike based lighting,” said the research team at the university. “Light affects people’s circadian rhythm. In order to improve biorhythm, we can adjust the light according to time zone and use a light source close to sunlight.”

Easy to build SunLike LED fixtures thanks to our LED strips & modules

With our LumiFlex700 SunLike LED strips you will have a brilliant natural light source easy to install over long distances, perfect for cove lights, architectural or indirect lighting. With our range of LinearZ SunLike LED modules you can easily build linear lighting fixtures thanks to the plug & play connection and Zhaga format.

By using our Casambi compatible PowerControler and the strips modules you can also easily build your own Human-centric lighting solution.

For example you can use a simple 2700K and 6500K combination of LED modules or a more complex one of 2700K, 4000K and 6500K.

Seoul Semiconductor SunLike CRI97+ Strips

SunLike LED Modules CRI97+