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Can light improve your cognitive performance

Can light improve your cognitive performance?

Wednesday 05 April 2023

Light is intrinsically and deeply connected to human well-being, in ways scientists are only beginning to fully understand. A growing body of research confirms this, and light-based treatments of numerous conditions are becoming more widely available to treat various diseases and ailments.

However, some research indicates certain light spectra may go a step further, by improving the performance of the human brain.

Impactful studies over the last five years have shown us that LED light sources which closely mirror the daylight spectrum, also known as daylight-enriched LEDs, offer improvements to processing speed, memory, visual accuracy, visual comfort and sleep quality.

Sunlike LED chips are capable of replicating the daylight spectrum with the highest degree of accuracy currently available. These are the same chips with which we deploy the Daylight Wavelength Technology™ in our Serious Lights range.

Light can improve processing speed and working memory

In 2021, the Division of Sleep Medicine at the Harvard Medical School conducted tests on sleep-deprived college students, testing their cognitive performance in a variety of tasks, while using differing light sources to test the subjects.


Across the board, college students tested under daylight-enriched LEDs performed better than their counterparts. In terms of test performance, the memory test showed an improvement of 5%, and performance speed was 3.2 times faster under daylight-enriched LEDs. These test subjects also stated that they felt significantly less drowsy, by a degree of up to 50%.

These results clearly show a significant improvement in speed and memory, which are both key to effective learning. The applications within the field of education are immediately obvious, but nearly all working environments could benefit if these findings are confirmed by further studies.

Daylight-replication improves visual comfort, alertness and mood

The Society of Light and Lighting ran a study in 2019 which examined the effects of different light spectra on the human condition. They compared standard, cheap LED light sources with a significant “blue light spike”, to daylight-enriched LED light sources, and measured the effects on the subjects.


The notorious “blue-light spike” is attributed to the high over-exposure of blue light wavelengths in cheap LED light sources. This is due to the way that white LED light sources are made. Cheaper LED light sources use a composition of phosphors which are artificially brightened with a high blue-light content. While cheap, these light sources are known to trigger a response that triggers a suppression in the production of melatonin, affecting sleep and causing greater eyestrain than light sources with a more balanced spectrum.

Volunteers who participated in the study found they had better visual comfort, felt more alert and felt happier under daylight-enriched LEDs than conventional, standard LEDs. These results are often stated anecdotally, but studies like this provide the data which succinctly portrays the truth behind how many people say they feel.

Light can improve sleep quality by up to 30%

The Seoul National University’s Medical School ran a study in 2018, which sought to demonstrate the effects of daylight-enriched LEDs on sleep. This study, run by Dr Kwangsuk Park tested sleep and morning alertness on a test group of 34 people.


This experiment showed that subjects using daylight-enriched LEDs would fall asleep 23% faster than those using standard LEDs. Moreover, sleep quality improved by an impressive 30%, measured by electrocardiograms of wakefulness and monitored activity of the sympathetic and parasympathetic nervous system.

Why is daylight so important?

Daylight is innately linked to human evolutionary biology, and our relationship with the solar cycle affects the production of many hormones in the human body. The circadian rhythm is the clearest example of this, but more research is being done to establish the full extent of the sun’s impacts on the brain, our moods and how we feel. The fact there is so much evidence demonstrating the way light can improve cognitive performance is a huge step in demonstrating the value of daylight-enriched light sources.

Improved daylight replication as a result of innovative companies seeking to shed better light will continue to be a sought-after asset in home design, workplaces, education centres and so many more places.

The research discussed here could be a catalyst to building environments which specifically cater to improving human performance. One can only imagine the impact the deployment of this technology could have on the education sector, complex, technical working environments as well as our more general working and living environments.

The future is certainly bright.


Cajochen C, Freyburger M, Basishvili T, et al. Effect of daylight LED on visual comfort, melatonin, mood, waking performance and sleep. Lighting Research & Technology. 2019;51(7):1044-1062. doi:10.1177/1477153519828419

Leilah K. Grant, Brianne A. Kent, Matthew D. Mayer, Robert Stickgold, Steven W. Lockley and Shadab A. Rahman, Daytime Exposure to Short Wavelength-Enriched Light Improves Cognitive Performance in Sleep-Restricted College-Aged Adults. Front. Neurol., 22 February 2021, Sec. Sleep Disorders, Volume 12 - 2021.

Tarquini R, Carbone A, Martinez M, Mazzoccoli G. Daylight saving time and circadian rhythms in the neuro-endocrine-immune system: impact on cardiovascular health. Intern Emerg Med. 2019 Jan;14(1):17-19. doi: 10.1007/s11739-018-1984-x. Epub 2018 Nov 28. PMID: 30488154; PMCID: PMC6668711.

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