The power of light to improve health, sleep, and productivity
At Health, Wellness, Sleep, we are passionate about harnessing the power of light to improve health, sleep, and productivity across all ages. With a deep understanding of the biological effects of light, both natural and artificial, we bring cutting-edge research into every solution we create.
Light isn’t just a tool for visibility
We know that light isn’t just a tool for visibility, it’s a critical factor in regulating our circadian rhythms, supporting mental and physical health, and enhancing overall well-being.
Our goal is to share this knowledge with those who can benefit the most, from businesses looking to boost productivity to families seeking better sleep.
We believe that light has the potential to be a
transformative element in the way we live and work
Scientific research
Our work is rooted in scientific research and a passion for improving lives through optimal lighting and sufficient exposure to daylight.
The role of light
By focusing on the role of light in sleep, mood, and cognitive function, we deliver tailored solutions that support better health outcomes.
Designing lighting
Whether it’s designing lighting for homes, workplaces, or healthcare environments, we’re committed to bringing the benefits of proper lighting to those who need it most.
Light, Circadian Rhythms, and Sleep
Sleep is not shaped only by what happens at bedtime. It is part of a 24-hour biological rhythm, and light reaching the eye is the principal environmental signal that helps to keep that rhythm aligned with day and night.
The timing of light matters as much as its brightness. Strong daytime light can reinforce the body’s daytime signal, while light during the evening or night can delay sleep timing or make it harder for the brain to recognise biological night. Light can also be used strategically to shift circadian timing earlier or later, but the response depends upon its timing, intensity, spectrum, duration, and the individual’s existing body-clock phase.
Health Wellness Sleep combines established circadian science, emerging photobiology, and nearly four decades of professional lighting knowledge. Our reviews consider daylight exposure, melanopic equivalent daylight illuminance at the eye, spectral characteristics, glare, colour quality, controls, evening light, nighttime darkness, and the way these elements change across the day.
This approach can help someone experiencing early waking or difficulty sleeping at the required time, as well as families, employers, and care organisations seeking to create more supportive routines and environments. A Circadian Light & Sleep Review turns complex research into practical, personalised opportunities that fit real homes, workplaces, responsibilities, and lives.
If light timing or the surrounding environment may be contributing to your sleep difficulties, contact us to discuss the most suitable review.
A Future Sleep, Light, and Circadian Retreat
Health Wellness Sleep is developing a small, private, science-led retreat in Scotland for senior leaders, founders, professionals, and frequent international travellers who want to understand their sleep more deeply, restore their daily rhythm, and step away from the pressures that may be affecting their wellbeing.
The proposed experience will bring together evidence-led education on sleep, circadian rhythms, daylight, artificial light, and emerging light research with restorative time outdoors, movement, relaxation, and carefully considered hospitality. The intention is to create an intimate, high-quality environment where each guest can explore how light, timing, travel, workload, and daily routines may be influencing their sleep and daytime energy.
We are carefully developing the retreat for later in 2027. Full details will be shared once the venue, programme, and specialist contributors are confirmed. To receive private updates or register your interest, please contact info@healthwellnesssleep.co.uk or call 0345 034 2026.
New Parents, Newborns, and the Developing Body Clock
Newborn babies do not arrive with an adult day–night rhythm. For approximately the first 50 to 100 days after birth, their sleep and feeding can be highly variable across the whole 24-hour day while the circadian system gradually matures. Published research places the development of more stable sleep–wake and hormonal rhythms broadly within the first 6 to 18 weeks, rather than on one fixed date. This unpredictability is a normal stage of development, not a parenting failure.
This important early-life window was reinforced during Lorraine Calcott’s recent completion of the British Sleep Society’s International Sleep Medicine Course. Combining current sleep science with specialist knowledge of light allows Health Wellness Sleep to explain what parents can realistically influence and what simply requires time, development, and patience.
Light and darkness are among the environmental signals that can help the developing circadian system begin to recognise day and night. Daylight, daytime activity, and normal household sounds can provide a clear daytime signal. During nighttime feeds and care, keeping the environment calm and as dark as safely practicable can preserve the contrast, using only the minimum gentle, localised light needed.
Supporting the parents is equally important. Repeated waking, early feeds, work demands, and limited daylight can disrupt the adults’ circadian rhythms as well as reducing their opportunities for sleep. Thoughtful changes to daylight routines, nursery lighting, feeding areas, evening light, and the parental sleep environment can make the whole household feel more manageable.
A Family Light & Sleep Review provides personalised, practical guidance for the home without imposing unrealistic schedules. We also offer employer masterclasses and organisational guidance to help workplaces support new parents with greater understanding, flexibility, and compassion during one of life’s most demanding transitions.
Teenagers, Light, and the Adolescent Body Clock
Teenagers are not simply choosing to be difficult when they struggle to sleep early or wake for school. Puberty is commonly accompanied by a later shift in circadian timing, while the biological build-up of sleep pressure may also occur more slowly. This can leave an otherwise healthy teenager naturally alert later in the evening and still biologically sleepy when an early alarm sounds.
Daylight during the earlier part of the day can help to reinforce the body’s daytime signal. A brighter day, appropriate time outdoors, and a calmer, lower-light evening can strengthen the contrast between daytime and biological night. Screens may contribute through their light, stimulating content, and the time they displace, so the answer is rarely as simple as confiscating a phone.
When school schedules, homework, sport, social life, and biology pull in different directions, both the teenager and the family can feel that sleep has become a battle. A Family Light & Sleep Review can explore light exposure, timing, routines, bedroom conditions, and the practical realities of family life, identifying manageable opportunities that respect the teenager’s developing biology.
We also provide talks and training for parents, schools, colleges, healthcare professionals, and other organisations that want to understand adolescent sleep and create more supportive expectations and environments. Contact Health Wellness Sleep to discuss the most helpful starting point for your family or organisation.
Video source: “Is artificial light killing us” – Dr.K.V.N.Rajesh &
Dr. Martin Moore-Ede (Former Harvard Professor) – YouTube
Older People, Light and Sleep
Ageing does not mean that we should simply accept poor sleep. Our circadian timing can become earlier, age-related changes to the eyes can alter the light reaching the retina, and changes in routine or mobility may reduce time spent outdoors. Together, these factors can weaken the important contrast between brighter days and darker evenings.
Research led by Professor Mariana Figueiro and other circadian-light specialists has found that carefully timed daytime lighting can improve some measures of sleep and mood in older people, including those living with dementia. Results vary between studies and between subjective and objective sleep measures, but the research highlights the value of creating a strong, appropriate light-dark pattern across the whole day.
Red and near-infrared light are also attracting growing interest. A 2026 randomised trial by Pin-Yu Chen and colleagues studied 59 adults aged 60 and over with early waking or difficulty remaining asleep. Participants reported improvements after two weeks of white light, near-infrared light, or a combination of both, although the researchers did not find corresponding changes in actigraphy or melatonin measurements. These early results make personalised, wavelength-aware approaches an exciting area for continued research and responsible exploration.
A Circadian Light & Sleep Review can examine daylight access, light at eye level, spectral characteristics, glare, timing, evening light, and nighttime darkness. Whether you are seeking help for yourself, supporting a relative, or responsible for a care environment, we can identify practical opportunities to create a more supportive 24-hour pattern of light.
To explore how a more considered pattern of light and darkness could support better sleep, daytime energy, and wellbeing for you or someone you care for, contact Lorraine for an initial conversation.
The Research
Cognitive consequences of sleep and sleep loss Matthew P. Walker
Although we still lack any consensus function(s) for sleep, accumulating evidence suggests it plays an important role in homeostatic restoration, thermoregulation, tissue repair, immune control and memory processing. In the last decade an increasing number of reports continue to support a bidirectional and symbiotic relationship between sleep and memory. Studies using procedural and declarative learning tasks have demonstrated the need for sleep after learning in the offline consolidation of new memories. Furthermore, these consolidation benefits appear to be mediated by an overnight neural reorganization of memory that may result in a more efficient storage of information, affording improved next-day recall. Sleep before learning also appears to be critical for brain functioning. Specifically, one night of sleep deprivation markedly impairs hippocampal function, imposing a deficit in the ability to commit new experiences to memory. Taken together, these observations are of particular ecologic importance from a professional and education perspective when considering that sleep time continues to decrease across all age ranges throughout industrialized nations.
Measuring Melatonin in Humans Susan Benloucif, Ph.D.; Helen J. Burgess, Ph.D.; Elizabeth B. Klerman, M.D., Ph.D.; Alfred J. Lewy, M.D., Ph.D.; Benita Middleton, Ph.D.; Patricia J. Murphy, Ph.D.; Barbara L. Parry, M.D.; Victoria L. Revell, Ph.D.
Melatonin synthesis from the pineal gland is regulated by the circadian pacemaker located in the suprachiasmatic nuclei and by ocular light exposure. Melatonin has a circadian rhythm that peaks during the night in normally entrained individuals. In the absence of light and other synchronizing signals, the rhythm of melatonin production persists with an elevation that occurs during the subjective, as opposed to the actual, night. There is a relatively direct anatomic pathway between the suprachiasmatic nuclei and the pineal gland, and comparatively few exogenous factors are known to affect melatonin concentrations (see Table 1 from Arendt, 2005, for a summary of these factors).1 As a result, the rhythm of melatonin production has been shown to re ect both the phase and, if collected over more than 1 cycle, the period of the endogenous circadian oscillator, thus providing a reliable means to estimate the timing of the internal circadian clock located in the suprachiasmatic nuclei.
The effect of light on our sleep/wake cycle Luc Schlangen
Evolution has shaped us to live in much more light than our modern indoor life gives us. We generally need most light in the morning and during the day, less in the evening, and the least possible at night. Ideally, this implies getting outside as much as possible during daytime, along with improved (24-hour) control of indoor lighting systems, so that we sleep better and wake up refreshed.
The role of lighting in promoting well-being and recovery within healthcare L.J.M. Schlangen
Light affects human beings in a variety of ways – visually, (photo-)biologically and psychologically. In healthcare facilities it can play a key role in promoting the recovery and well-being of patients. There is a clear correlation between daytime light exposure and the patient’s perceived quality of life. The more time spent in daylight, or in daylight-like artificial light, the better the patient’s visual performance and comfort, mood, sleep-wake rhythm, concentration, alertness and performance. Clinical parameters such as recovery/length of stay, depression, pain medication and cognitive decline are likewise positively influenced by adequate daytime light exposure. There is also strong evidence that light – critical to human functioning – can be extremely beneficial to staff in healthcare settings as well as patients.
Cognitive consequences of sleep and sleep loss W.P Walker
Abstract – Although we still lack any consensus function(s) for sleep, accumulating evidence suggests it plays an important role in homeostatic restoration, thermoregulation, tissue repair, immune control and memory processing. In the last decade an increasing number of reports continue to support a bidirectional and symbiotic relationship between sleep and memory. Studies using procedural and declarative learning tasks have demonstrated the need for sleep after learning in the offline consolidation of new memories. Furthermore, these consolidation benefits appear to be mediated by an overnight neural reorganization of memory that may result in a more efficient storage of information, affording improved next-day recall. Sleep before learning also appears to be critical for brain functioning. Specifically, one night of sleep deprivation markedly impairs hippocampal function, imposing a deficit in the ability to commit new experiences to memory. Taken together, these observations are of particular ecologic importance from a professional and education perspective when considering that sleep time continues to decrease across all age ranges throughout industrialized nations. ?? 2008 Elsevier B.V. All rights reserved.
Metabolic consequences of sleep and sleep loss Eve Van Cauter, Karine Spiegel, Esra Tasali, Rachel Leproult
Abstract – Reduced sleep duration and quality appear to be endemic in modern society. Curtailment of the bedtime period to minimum tolerability is thought to be efficient and harmless by many. It has been known for several decades that sleep is a major modulator of hormonal release, glucose regulation and cardiovascular function. In particular, slow wave sleep (SWS), thought to be the most restorative sleep stage, is associated with decreased heart rate, blood pressure, sympathetic nervous activity and cerebral glucose utilization, compared with wakefulness. During SWS, the anabolic growth hormone is released while the stress hormone cortisol is inhibited. In recent years, laboratory and epidemiologic evidence have converged to indicate that sleep loss may be a novel risk factor for obesity and type 2 diabetes. The increased risk of obesity is possibly linked to the effect of sleep loss on hormones that play a major role in the central control of appetite and energy expenditure, such as leptin and ghrelin. Reduced leptin and increased ghrelin levels correlate with increases in subjective hunger when individuals are sleep restricted rather than well rested. Given the evidence, sleep curtailment appears to be an important, yet modifiable, risk factor for the metabolic syndrome, diabetes and obesity. The marked decrease in average sleep duration in the last 50 years coinciding with the increased prevalence of obesity, together with the observed adverse effects of recurrent partial sleep deprivation on metabolism and hormonal processes, may have important implications for public health.
Breast cancer and circadian disruption from electric lighting in the modern world MBC Aries PhD, MSc, MPJ Aarts MSc and J van Hoof PhD, MSc, Eur Ing
Abstract – Breast cancer is the leading cause of cancer death among women worldwide, and there is only a limited explanation of why. Risk is highest in the most industrialized countries but also is rising rapidly in the developing world. Known risk factors account for only a portion of the incidence in the high-risk populations, and there has been considerable speculation and many false leads on other possibly major determinants of risk, such as dietary fat. A hallmark of industrialization is the increasing use of electricity to light the night, both within the home and without. It has only recently become clear that this evolutionarily new and, thereby, unnatural exposure can disrupt human circadian rhythmicity, of which three salient features are melatonin production, sleep, and the circadian clock. A convergence of research in cells, rodents, and humans suggests that the health consequences of circadian disruption may be substantial. An innovative experimental model has shown that light at night markedly increases the growth of human breast cancer xenografts in rats. In humans, the theory that light exposure at night increases breast cancer risk leads to specific predictions that are being tested epidemiologically: evidence has accumulated on risk in shift workers, risk in blind women, and the impact of sleep duration on risk. If electric light at night does explain a portion of the breast cancer burden, then there are practical interventions that can be implemented, including more selective use of light and the adoption of recent advances in lighting technology and application. CA Cancer J Clin 2014;64:207-218. © 2013
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Red and Near-Infrared Light Research
Why red and near-infrared light are changing the health conversation
Natural daylight contains a broad range of wavelengths, including red and near-infrared energy that is limited or absent in many common indoor LED spectra. This difference is attracting serious scientific attention because specified wavelengths are capable of penetrating biological tissue and interacting with cellular processes that ordinary visual lighting calculations do not consider.
Foundational research by scientists including Tiina Karu, Margaret Wong-Riley, Janis Eells, and Harry Whelan has explored how carefully controlled red and near-infrared light can influence cytochrome c oxidase, mitochondrial signalling, and wider cellular responses. Praveen Arany and other researchers have extended the conversation into tissue repair, inflammation, regenerative medicine, and defined clinical applications. The effects depend upon wavelength, dose, timing, tissue, and biological context, but this growing body of work provides a compelling scientific basis for looking beyond vision and energy efficiency when we consider light and health.
Current research is also examining the wider solar spectrum and asking whether modern indoor environments provide all the light-related information that human biology evolved to experience. These questions are opening valuable new conversations about daylight, spectral balance, photobiomodulation, and the next generation of integrative lighting.
Through an evidence-led Light and Health Review, we assess daylight access, spectral characteristics, light at eye level, timing, glare, colour quality, and controls. This enables individuals and organisations to understand the research, identify practical opportunities, and explore emerging light strategies with appropriate care and purpose.
The accompanying video presents astrophysicist Robert Fosbury’s expert perspective on infrared light and its relationship with life. His developing work offers an interesting framework for discussion alongside the wider peer-reviewed evidence.
Astrophysicist on Infrared Light & Life Interactions | Robert Fosbury
More information – Download Infrared Light and Its Profound Impact on Health
Blue light benefits and impacts
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Regulating circadian rhythms
Blue light, particularly from artificial sources like digital screens and LED lighting, has become a key area of focus due to its potential effects on our health. While blue light from natural sunlight is essential for regulating circadian rhythms and maintaining alertness during the day, excessive exposure, particularly in the evening, can disrupt sleep patterns. Research has shown that blue light exposure at night suppresses melatonin production, the hormone that regulates sleep, leading to delays in sleep onset and reduced sleep quality.
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Eye health
Excessive blue light exposure is not only linked to poor sleep but has also been associated with eye strain and discomfort, particularly with prolonged screen use. Studies have found that digital eye strain is a growing issue due to the constant exposure to blue light from screens (American Optometric Association). While research on the long-term effects of blue light on eye health is still developing, there is a clear indication that excessive exposure contributes to discomfort and could potentially impact long-term vision.
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Myopia on the rise
A growing body of evidence has established a strong link between increased screen time and the rising rates of myopia (near-sightedness), particularly in children and adolescents. Studies, such as those published in The Lancet, have shown that extended near-work activities, including screen time, contribute significantly to the development and progression of myopia, highlighting the need for proper light management and breaks from screen exposure to protect vision in the digital age.
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Limit screen exposure
To mitigate these impacts, it is important to limit screen exposure, especially before bed, and encourage natural light exposure during the day, even on dull days. These practices support our circadian rhythms and eye health, promoting better sleep quality and reducing the risk of myopia development in younger populations.
Love working from home again, with lighting that works as hard as you do.
Why Daylight Matters for Health
Daylight is one of the most powerful and biologically rich influences in our environment. Light reaching the eye provides essential timing information to the circadian system, helping the body distinguish morning, daytime, evening, and night. Its intensity and spectral composition also change naturally across the day in ways that most indoor environments do not reproduce. (National Institutes of Health).
International scientific recommendations recognise the importance of receiving strong light during the day, preferably from daylight, alongside much lower light exposure during the evening and darkness during sleep. Regular daytime light can help strengthen circadian timing, support daytime alertness, and prepare the body for sleep at the appropriate time. (American Psychological Association).
Sunlight also enables vitamin D production when ultraviolet B radiation reaches uncovered skin. Vitamin D contributes to bone health, calcium regulation, immune function, and several other biological processes, as explained in the National Institutes of Health Vitamin D Fact Sheet. The amount produced varies considerably with season, latitude, time of day, skin pigmentation, age, clothing, and individual circumstances.
Researchers including Professor Alistair Nunn are encouraging a wider conversation about whether modern indoor lifestyles and an understandable focus on ultraviolet risk have caused us to overlook other biologically relevant parts of the solar spectrum. Emerging work is examining the possible importance of red and near-infrared wavelengths, mitochondrial signalling, and the difference between full-spectrum daylight and common indoor lighting. These developing areas add to the established circadian and vitamin D evidence and deserve serious, proportionate investigation.
Seasonal changes in daylight can also affect mood and sleep timing, with the American Psychological Association providing further information about sunlight and seasonal affective disorder. The linked video takes a deliberately challenging look at sunlight, vitamin D, and current health assumptions. It is included to encourage informed discussion alongside the wider peer-reviewed evidence.
A Circadian Light & Sleep Review can help you understand how daylight, indoor lighting, evening light, and darkness interact across your own 24-hour day. We translate established research and important emerging ideas into practical opportunities suited to your home, work, lifestyle, and sleep timing.
Video Source: Vitamin D Expert: The Fastest Way To Dementia & The Dangerous Lie You’ve Been Told About Sunlight! (YoutTube)
Frequently Asked Questions – Light and Health
Why is sleep essential to our well-being?
Why is sleep essential to our well-being? The role of light in regulating sleep patterns cannot be overstated and we help you to optimise light exposure both with daylight and artificial sources to bring about healthy improvements to sleep. No drugs or apps, just plain old-fashioned sleep/wake entrainment using billions of years of natural light interventions and a lot of cutting-edge research backed support. If we don’t sleep well every part of our life suffers, so getting this right should be at the core of everyone’s daily life. We can help you, get in touch.
New parents and newborns, why is setting a sleep schedule so challenging?
Newborn sleep is not organised like adult sleep. For approximately the first 50 to 100 days, sleep and feeding may occur unpredictably across the day and night while the circadian system gradually matures. Research has found that biological rhythms emerge sequentially during the early months, so trying to impose a rigid timetable too soon can create frustration when development, rather than parenting, is setting the pace.
Parents can still provide helpful environmental signals. Daylight, normal daytime activity, and social interaction can make daytime distinct, while calm surroundings, darkness wherever safely practicable, and only the minimum gentle, localised light needed for nighttime care can help preserve the difference between day and night. The aim is to provide a reassuring daily pattern, not to force sleep before the baby’s biology is ready.
A Family Light & Sleep Review considers the household’s daylight pattern, nursery and feeding-area lighting, nighttime care, the parents’ own light exposure, and the realities of work and family life. Together, we can identify manageable changes that support the baby’s developing rhythm while helping tired parents create a calmer and more sustainable environment.
Why can’t my teenage children get up in the morning?
During puberty, circadian timing commonly shifts later, while the biological pressure to sleep may build more slowly. A teenager can therefore be genuinely alert during the evening and still feel biologically sleepy when an early alarm sounds. Early school times, homework, activities, and social life can then reduce the opportunity for sufficient sleep.
Light is an important part of this picture. Daylight and a brighter environment earlier in the day can reinforce the daytime signal, while a calmer, lower-light evening can support the transition towards biological night. Screens may contribute through their light, stimulating content, and the time they displace, rather than blue light being the only consideration.
A Family Light & Sleep Review can explore the teenager’s daily light exposure, sleep timing, routines, bedroom environment, and practical commitments. We can then identify realistic changes that respect adolescent biology and help sleep feel less like a daily battle for the whole family.
As we age, why can sleep become more difficult or fragmented?
Sleep often changes as we grow older, but persistent poor sleep should not simply be accepted as inevitable. Circadian timing may move earlier, age-related changes to the eyes can alter the light reaching the retina, and changes in mobility or routine may reduce exposure to strong daytime light. Together, these factors can contribute to earlier waking, daytime tiredness, and more fragmented sleep.
Research by Professor Mariana Figueiro and other circadian-light specialists suggests that stronger, appropriately timed daytime light, combined with dimmer evenings and darkness at night, can reinforce the daily light-dark pattern and improve some sleep and mood measures in older people. Responses vary between individuals and settings, which is why timing, spectrum, intensity, and the light reaching the eye all deserve consideration.
Emerging research is also investigating red and near-infrared light. A 2026 randomised trial led by Pin-Yu Chen reported improvements in subjective sleep measures among adults aged 60 and over following white light, near-infrared light, or a combination of both. Objective sleep and melatonin measures did not change, but the findings add an intriguing new direction to the developing science of personalised light interventions.
A Circadian Light & Sleep Review can help older adults, families, carers, and care teams understand the existing 24-hour light environment and identify practical opportunities involving daylight, indoor lighting, evening light, and nighttime darkness.
Why are red and near-infrared light attracting scientific attention?
Red and near-infrared light are attracting growing scientific interest because particular wavelengths can penetrate biological tissue and are being studied for their influence on mitochondrial electron transport, cellular signalling, inflammation, visual function, tissue repair, metabolism, and brain activity. Researchers including Tiina Karu, Janis Eells, Praveen Arany, Michael Powner, and Paolo Cassano have investigated different aspects of this field, from foundational mitochondrial and retinal biology to wound healing, cognition, and emerging human applications.
Human trials have reported promising responses in some carefully defined photobiomodulation applications. Other possibilities are being explored through small human studies, animal and cellular research, and developing scientific hypotheses. A 2026 bioRxiv preprint from Robert Fosbury, Roger Seheult, Scott Zimmerman, and Glen Jeffery proposes a physical framework through which photons might assist mitochondrial electron-transfer processes. This is a non-peer-reviewed proposed framework rather than established clinical proof, but it raises important questions about the biological differences between the full solar photon field and the spectra produced by common indoor LEDs.
We follow these developments closely and use them to inform evidence-led assessments of daylight, spectral content, intensity, timing, and controls in homes and workplaces. This enables clients to explore proportionate innovation, understand which findings are ready to inform practice, and prepare their environments for the next generation of light-and-health knowledge.
Can energy-efficient lighting also support human biology?
Yes—but energy efficiency alone does not describe the quality or biological potential of light. Conventional white LEDs can provide excellent visual performance while producing a very different spectrum and daily pattern from natural daylight, often with limited longer-wavelength red and little or no near-infrared output. Researchers including Glen Jeffery, Robert Fosbury, Alistair Nunn, and Scott Zimmerman are exploring why these spectral differences may matter to mitochondrial function, cellular signalling, and wider human biology.
This is an active and exciting field. Strong evidence already demonstrates the importance of light timing and melanopic stimulation for circadian rhythms, while smaller human studies, laboratory research, and developing scientific frameworks are expanding the conversation around red and near-infrared wavelengths. Emerging evidence gives us an opportunity to measure, test, and innovate responsibly rather than waiting for every question to be settled.
Our assessments consider daylight access, vertical light at the eye, melanopic equivalent daylight illuminance, spectral content, glare, colour quality, controls, and how light changes across the day. This helps clients explore practical ways to create environments that are energy efficient, visually excellent, and ready for the next generation of light-and-health knowledge.
What is emerging research exploring about red and near-infrared light?
Red and near-infrared photobiomodulation is an exciting and rapidly developing field. Small human studies have reported effects on specific physiological measures, including post-meal blood glucose in healthy adults, while laboratory and clinical research is exploring how carefully specified light may influence cellular metabolism and support people in particular healthcare settings. This work is most useful when interpreted precisely, because wavelength, dose, timing, tissue, health condition, and study design can all change the result.
Our consultancy follows this evolving research closely and translates it into clear, responsible guidance about light exposure and supportive environments. We help clients understand established knowledge, promising early findings, and practical opportunities that may be worth exploring with an appropriately qualified clinical professional.
I have heard the blue light from screens and LED are bad for us, tell me more?
Blue light, particularly from artificial sources like digital screens and LED lighting, has become a key area of focus due to its potential effects on our health. While blue light from natural sunlight is essential for regulating circadian rhythms and maintaining alertness during the day, excessive exposure, particularly in the evening, can disrupt sleep patterns. Research has shown that blue light exposure at night suppresses melatonin production, the hormone that regulates sleep, leading to delays in sleep onset and reduced sleep quality.
A growing body of evidence has also established a strong link between increased screen time and the rising rates of myopia (near-sightedness), particularly in children and adolescents. Studies, such as those published in The Lancet, have shown that extended near-work activities, including screen time, contribute significantly to the development and progression of myopia, highlighting the need for proper light management and breaks from screen exposure to protect vision in the digital age.
Have we become too cautious about sunlight?
Professor Alistair Nunn and The Guy Foundation have drawn attention to an important question: have modern indoor lifestyles, and an understandable focus on ultraviolet risk, caused us to overlook the wider biological value of sunlight? Humans evolved under the full solar spectrum, and daylight provides powerful information to our circadian system while also supporting vitamin D production and other physiological processes that continue to be actively researched.
Nunn’s work presents sunlight as part of the environmental conditions to which life is biologically adapted. This encourages a more balanced approach – not fearing daylight or treating every exposure as harmful, but rebuilding regular contact with natural light while recognising that skin type, season, location, health history, exposure duration, and the UV index all matter.
The aim is appropriate sunlight exposure without burning, using timing, shade, clothing, or sunscreen according to individual circumstances and UV conditions. Through a Circadian Light & Sleep Review, I help clients understand when and how they experience daylight and develop a realistic 24-hour light strategy that fits their sleep timing, work, lifestyle, and personal needs.
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