
Is there a simple, scientific approach to satisfy human biological lighting needs? You bet. Allow me to introduce: The Melanopic Ratio!
Henrik Clausen, the Director of the Fagerhult Lighting Academy, stands at the forefront of innovation, sustainability, and smart lighting. With a commitment to creating a truly effective lighting environment, Henrik emphasises the importance of understanding the intricate relationship between light and our biological rhythms.
In this exploration, Henrik introduces the concept of the Melanopic Ratio.
It's not just about lighting up a space for visibility; it's about synchronizing with our biological rhythms for a genuinely effective lighting environment.
When it comes to measuring light, we often talk about lux, which describes the brightness hitting an area or filling a room. But did you know there's more to it than meets the eye? Traditionally, we've focused on "photopic lux," the kind of light our eyes need for clear vision. But here's the game-changer: the world of lighting planning now includes "Melanopic lux," the unit that gauges how light affects the receptors governing our biological circadian rhythm. It's all about the amount and the spectrum of light we experience, and it plays a significant role in our sleep quality and overall well-being.
Picture this: You step out on a bright, sunny morning, and you instantly feel more alert. That's the kind of awakening "melanopic" light provides, and electric lighting can mimic this natural spectrum, which helps support our circadian rhythm.
In settings where people spend extended periods, like offices and schools, a consistent circadian rhythm can make a world of difference. Healthcare environments, such as hospitals and clinics, are another prime example, where a well-balanced circadian rhythm benefits both patients and healthcare providers.
Enter the Melanopic Ratio. It's your ace in the hole if you're into spaces that cater to human biological needs. This factor, known as Melanopic Daylight Efficacy Ratio (MDER), plays a pivotal role in lighting planning. It calculates how much a light source contributes to melanopic lux, which measures light vertically at eye level. Since daylight is the reference point for our circadian rhythm, it serves as the basis for Melanopic Ratio.
Here's the nitty-gritty: Melanopic Ratio compares the spectral composition of a light source with daylight. Armed with a light's Melanopic Ratio, you can effortlessly determine its melanopic lighting intensity. This allows us to create lighting setups that hit the bullseye for both visual and biological lighting needs.
But not all lights are created equal. Luminaires with high intensity and a higher color temperature usually boast a favorable Melanopic Ratio.
I recommend following the recommendations of the International Commission on Illumination (CIE). They're all about keeping things standardized and have introduced the concepts of MDER and MEDI in the upcoming global lighting standard. While these aren't mandatory, they're a valuable addition. We take your experience and health seriously, so we provide Melanopic Ratio data (MDER) at the diode level per luminaire for full transparency.
We're committed to sharing the Melanopic Ratio because good lighting isn't just about visibility; it's about aligning with your biological clock. It's as fundamental as ensuring your workspace is comfortably heated and well-ventilated.
By making Melanopic Ratio data available for all luminaires, we're contributing to a holistic approach to future workplaces. Property owners can invest wisely, and lighting designers can create spaces where people thrive. With just one factor per luminaire, you can delve into the world of Melanopic Ratio (MDER) at the diode level, exploring how different setups impact visual and biological lighting intensity and energy efficiency. It also simplifies documentation, especially for building certification purposes.
Remember, there's no shortcut to perfect lighting. Melanopic Ratio is crucial, but it's not the only player in the game. We must still consider all aspects of lighting, including visual and emotional elements. Meeting standards and adhering to norms for glare and luminance remains imperative. Excessive lighting intensity and improper light angles can lead to discomfort and glare.
We cherish natural daylight, but trying to mimic it round the clock isn't energy-efficient. Each lighting system must be thoughtfully tailored to meet users' needs, room layouts, and daylight availability.
Good lighting is all about respect—for people and the environment. Melanopic Ratio is a key factor in striking the right balance between health, sustainability, and economic efficiency. While biologically active lighting and advanced control systems may demand more energy, they represent an investment in human well-being without compromising the environment or the bottom line.
As always, energy conservation is a priority. Research indicates that our circadian rhythm responds best to a "light shower" with cooler light for a period ranging from 30 minutes to three hours in the morning. After that, both lighting intensity and color temperature can be toned down, provided they meet the lighting standard's normative requirements. Smart lighting control and tunable white lighting systems enable us to create energy-efficient setups that adhere to the standards—500 photopic lux on work surfaces and a recommended 250 melanopic lux for two hours in the morning.
In healthcare environments, there's ample room to create a supportive lighting environment in an energy-efficient manner. Patients often remain bedridden, and horizontal light exposure allows us to achieve recommended lighting levels with lower energy consumption.
Embrace daylight—it doesn't matter where it comes from, if it delivers the right intensity and quality. By integrating natural light and implementing effective control systems, you can maintain appropriate lighting levels while minimizing energy consumption.
Choose your luminaires thoughtfully. A high Melanopic Ratio often means you can reduce photopic lighting intensity and save energy. However, it's essential to keep in mind that every individual has unique needs, and a well-designed lighting plan should cater to those distinctions.

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Melanopic lux: lighting for education influenced by human biology
Light is essential in our daily lives, influencing our ability to see, overall well-being and performance. In educational environments, lighting quality can significantly impact students' focus, mood, and energy levels. So, how do we know what is the right amount and quality of light for this setting? Traditionally, light has been measured in lux, a unit of measurement for the intensity of light. It's used to measure how much light falls on a surface or the amount of light in a given space. One lux is the amount of light that falls on a surface that is one square meter in area when one lumen of light is spread out evenly. Recent advancements in research have unveiled the importance of melanopic lux, which goes beyond mere visibility. This measures how effectively light stimulates specific eye cells that regulate crucial non-visual functions such as sleep and alertness. In classrooms and lecture theatres, the melanopic ratio has become vital in lighting design, enabling educators to create spaces that support visual tasks and align with students' biological rhythms. In this article, we explore how lighting solutions can align with our biology, and how this helps to create optimum conditions for educational environments. The science of vision and light The human eye is a remarkable organ designed for high-resolution colour vision within a small area (approximately 2 degrees of the visual field) while relying on peripheral vision for motion detection. This dual-function system, shaped by evolution for survival, continues to influence how we perceive and interact with our surroundings. Our eyes are particularly susceptible to green and yellow light, reflecting our evolutionary adaptation to naturally lit environments. In contrast, blue light, which is chief in modern LED lighting, requires higher intensity to be perceived at the same level. Effective lighting design carefully considers brightness, timing, and distribution to support visual clarity and biological functions like mood and alertness. For example, exposure to bright light in the morning helps regulate circadian rhythms, boosting alertness and mitigating the effects of seasonal darkness. This is particularly important in educational environments, such as schools and universities, where lighting impacts mood, focus, and overall performance. Our Organic Response system provides an innovative solution tailored for these spaces. This smart lighting technology automatically optimises light levels, featuring daylight-responsive sensors and advanced occupancy detection, maintaining a balance between natural and artificial light. Doing so supports visual comfort and reduces energy consumption, making it an ideal choice for creating dynamic, efficient, and student-friendly learning environments. To further support students, well-lit spaces with minimal glare are essential for reducing eye strain and maintaining focus during extended study sessions. Adjusting light intensity and colour temperature for different tasks—such as reading, group discussions, or creative activities—enhances light's visual and non-visual effects. By integrating thoughtful lighting strategies like those offered by Organic Response, educational environments can promote healthier, more productive, and engaging learning experiences. Integrative lighting: Supporting health and well-being. Integrative lighting (also referred to as human-centred lighting) combines visual and non-visual benefits (such as emotional effects) to support biological rhythms and psychological well-being. This approach goes beyond traditional lighting solutions by considering how light impacts circadian rhythms and hormonal balance. Light exposure in the morning is critical for suppressing melatonin (the sleep hormone) and increasing cortisol (the alertness hormone). Proper timing helps align students' natural rhythms with school schedules, which often require a lot of focus. Consistent exposure to bright, cool light early in the day can enhance energy levels and cognitive performance. The melanopic ratio compares the spectral composition of a light source with daylight. Using this information, you can determine its melanopic lighting intensity. This enables the design of lighting setups that precisely meet both visual and biological lighting needs. Lighting recommendations for educational spaces Each learning environment has unique lighting needs. Libraries benefit from direct lighting on the floor, paired with ambient lighting on walls and ceilings. Vertical shelf lighting (200-300 lx) makes it easier to browse titles. Lecture halls, on the other hand, require glare-free, comfortable lighting with flexible control, ideally with pre-programmed scenarios. In auditoriums and classrooms, strong vertical lighting is crucial for clear visual communication, especially over greater distances, enhancing facial expressions and engagement. General lighting recommendations apply to all educational spaces. Our solutions meet industry standards, ensuring reading and writing areas maintain 500 lx for effective visual tasks. Using daylight-responsive sensors for luminaire rows can reduce energy consumption while maximising natural light. The number and arrangement of luminaires should be adjusted based on the room's size and function to ensure consistent illumination. The role of dynamic lighting A Double Dynamic lighting system can be a game-changer in educational environments. It allows for intensity and colour temperature adjustments to match the specific needs of activities, from quiet reading sessions to collaborative group work. Fagerhult's distinct approach to lighting means that our design is human-centric; we integrate scientific insight into light and human psychology, creating environments that support academic performance and well-being. Our focus on energy efficiency also means our advanced control systems optimise light usage while minimising energy consumption, contributing to a building’s sustainability goals. The customisable setting and flexible solutions ensure that educational environments can create tailored lighting profiles for different times of the day or specific learning activities. Long-term benefits of melanopic lighting Melanopic lighting, designed to mimic the natural light spectrum, helps regulate the circadian rhythm, which is essential for maintaining focus, energy, and emotional balance. In classrooms and study areas, proper lighting can reduce eye strain, improve sleep patterns, and enhance mood, which are critical for students' mental health and academic performance. By incorporating lighting that aligns with our biological needs, schools and universities can foster healthier, more productive learning environments,. This is particularly important during the winter months when daylight is limited. Whether through advanced tuneable white light systems, designs that maximise daylight, or energy-efficient solutions, we are dedicated to leading the way in lighting innovation for educational environments, delivering brighter futures—one classroom at a time.
Enter the age of tailored lighting
Light allows us to see where we otherwise couldn’t. But, science continues to discover more about the profound influence of light over our physiological and psychological well-being. Our relationship with light is deeply ingrained in our biology. It affects our sleep cycles, productivity, mood, and overall health. Yet most artificial lighting still overlooks these vital interactions, and is designed predominantly around the average individual rather than a diverse demographic. This bias in lighting conditions warrants a closer look and a call for tailored solutions to cater to the varied lighting needs of the broader population. Time changes the eye Our ability to perceive light, decipher colours and detect shapes varies across the age spectrum due to physiological changes in our visual system. In our youth, the crystalline lens in our eyes - responsible for focusing light onto the retina - is clear and flexible. The number of photoreceptors - the light-sensitive cells in the retina - is at its peak then. This means a young individual’s visual system can effectively process the incoming light, ensuring optimal visual acuity. However, as we age, the lens of our eyes begins to yellow and harden, a phenomenon known as presbyopia. The pupil - the opening that allows light into the eye - also reduces in size, limiting the quantity of light that can reach the retina. Concurrently, the number of photoreceptors begins to decline, and the retinal nerve fibres responsible for transmitting visual information to the brain start thinning. These age-related changes significantly decrease the efficiency of the visual system in capturing and processing light. Light also plays a crucial role in regulating our internal biological clock: the circadian rhythm. This intrinsic timekeeper governs many physiological processes, including sleep-wake cycles, hormone secretion, digestion, and body temperature. Light, particularly in the blue wavelength, is the primary external cue that helps to synchronise our internal clocks with the environmental light-dark cycle. Blue light suppresses the production of melatonin, a hormone that signals sleep, thereby increasing alertness and shifting our circadian rhythm to align with the day-night cycle. Our sensitivity to blue light wanes with age due to the yellowing of the lens and a decrease in retinal sensitivity. This diminished blue light sensitivity can disrupt the synchronisation of the circadian rhythm, potentially contributing to sleep disorders and other health issues often observed in older adults. Older individuals need more light for visual tasks and more light, especially blue light, to maintain a healthy circadian rhythm. Indeed, a 40-year-old needs twice as much light as a 20-year-old, while a 60-year-old requires four times the light of a 20-year-old. Custom as the standard These differences in light requirements make a compelling case for a shift in our current lighting standards from a one-size-fits-all policy to a customised lighting as the norm. Colour temperature plays a pivotal role in catering to the visual needs of older individuals. Due to the yellowing of lens and cornea, blue light transmission can be achieved through higher colour temperatures, around 5000-6500K. These fall in the blue-white spectrum and mimic natural daylight to aid the circadian rhythm. Direct and indirect lighting schemes can be employed depending on the task at hand, while dimmable lights allow users to adjust light intensity according to the specific needs of a task or time of day. Uniformity in illumination and minimising flicker are crucial for ageing eyes, which are more sensitive to shadows and flickering. Tailoring the duration of light exposure to align with natural circadian rhythms can enhance sleep and overall well-being, necessitating brighter, blue-enriched light during the day and warmer, dimmer light in the evening. The goal here is not just to increase light intensity but to provide a well-rounded lighting solution that caters to individuals' spectral, spatial, and temporal lighting needs. This requires an innovative shift in lighting design from static solutions to dynamic systems that can adapt to the varying needs of the user throughout the day. Light that reflects you The application of tailored lighting is also highly context specific. In educational settings, tailored lighting can create optimal visual conditions and enhance student alertness, potentially improving academic performance. In workplaces where the age of employees can range broadly, lighting solutions need to account for these age-related differences, providing sufficient light for older employees without creating discomfort for younger people. Care facilities, where residents have unique and often complex needs, can also benefit from a more human-centric lighting approach. For example, research suggests that patients with dementia could significantly benefit from tailored lighting that aligns with their circadian rhythms, possibly leading to improved sleep quality, mood, and overall well-being. This transition towards tailored lighting demands a revolutionary change in design practices and standards. We need to shift from a generic approach to a human-centric model focussing on individuals and their unique light needs. This concept is encapsulated in Human Centric Lighting (HCL). This approach promotes the development of lighting solutions beyond functionality and visual comfort, addressing health, well-being, and productivity, regardless of the user’s age. Implementing HCL requires careful planning from the conception of a building, extending to retrofits, and spanning both commercial and residential environments. From the choice of light sources to the control systems, every aspect of lighting design should be carefully evaluated and selected to cater to the users’ needs. For instance, modern control systems like Organic Response allow for dynamic control of light intensity, colour temperature, and distribution, adapting to the changing needs of the users throughout the day and their movement around a building. Fagerhult's Organic Response represents a significant advancement in the realm of human-centric lighting, providing dynamic and adaptive lighting solutions that can address the differential needs of various age groups. At its core, Organic Response is a lighting control technology that allows each luminaire to communicate with its neighbours, responding in real-time to occupancy and ambient light levels. A space right for everyone Tailored lighting must also incorporate the specific use of a facility. For instance, a factory floor, a hospital ward, or a classroom will each have distinct lighting requirements. By understanding the tasks performed, the demographic of the users, and the desired outcomes, lighting solutions can be designed to promote productivity, safety, and wellness in each unique context. The ultimate vision of HCL and tailored lighting is not just about providing sufficient light to see but creating environments where light positively impacts human health and well-being. In recognising the intricate interplay between light and our biology, we can use lighting as a powerful tool to enhance our lives. From supporting productivity in offices to improving quality of life in care facilities, tailored lighting plays a transformative role in changing our environments so they can be illuminated just right for people of all ages.