
Harmonizing Light Dosimetry: Illuminating a Unified Path
Henrik Clausen is Director of the Fagerhult Lighting Academy, as well as Associate Professor at Aalborg University in Copenhagen. He is tasked with keeping Fagerhult’s general lighting knowledge up to date, and that includes reading many scientific papers.
Sharing his thoughts on papers he finds especially interesting and/or thought-provoking is one of the aspects of this role he loves.
Recently, Henrik posed the question - ‘Can we dose the right amount of light?’
To a certain degree, we can. But, there is an underlying concern about light dosimetry, and here, Henrik would love to give you a little more to think about...
In the vast canvas of scientific exploration, the study of light's effects is like an artist's palette of endless colours. Just as different artists apply unique brushstrokes to create their masterpieces, researchers approach light dosimetry with their own methods and metrics.
These variations, while showcasing the diversity of scientific exploration, also raise a challenge — a challenge to compare and align different works of art or in this case scientific results, for a clearer, unified understanding.
Consider this: scientists from various corners of the world, armed with their tools and knowledge, delve into the realm of light dosimetry. They strive to capture the intricacies of light's influence on our well-being, just like artists capture the essence of light in their paintings. And, just as each artist's style brings forth a different story, each scientist's approach to dosimetry has the potential to yield unique insights.
These diverse approaches are like different colours on the canvas, representing the nuances of light's impact. But, imagine trying to create a cohesive artwork by blending those colours without a shared understanding of their shades and tones.
Similarly, without a common framework for measuring and quantifying light's visual, emotional, and biological effects, scientists find themselves facing a complex puzzle - how to compare their findings in a meaningful, standardised and comparable way?
It's as if a symphony is being played, with each musician interpreting the notes in their own, slightly different way. Yet, to create harmony, the musicians must follow a conductor's guidance and stay in tune with each other. Similarly, the field of light dosimetry needs a conductor - a common frame of reference that guides scientists in choosing the right "notes" (metrics and procedures) to measure light's impact consistently across studies conducted on different locations in time and space.
Imagine a world where different dosimetry studies are like puzzle pieces that fit together seamlessly. By aligning their metrics, scientists can create a clearer picture of how light affects us. This alignment doesn't have to be stifling creativity; rather, it's about providing a shared language that allows scientists to communicate their findings, methods and procedures effectively to their peers, for them to understand, compare and reproduce these findings, fostering a deeper mutual understanding and thereby the very understanding of light's biological and non-visual role in all our lives.
In this quest for alignment, researchers aim to bridge the gap between various brushstrokes of scientific exploration. By using common metrics and methods, they can enhance the comparability of their work. This, in turn, leads to a broader perspective on the effects of light, helping us understand the dosage of light we need for optimal health and well-being.
Just as artists contribute to a collective understanding of the world through their creations, scientists too, contribute to our understanding of light's impact through their studies. By harmonising their efforts, they create a symphony of knowledge that benefits us all.
So, as the world of light dosimetry continues to evolve, scientists work towards aligning their brushstrokes of discovery, painting a clearer, more harmonious picture of the profound effects of light on our lives.

Light and people
Light has always been a prerequisite for human existence. Inspired by daylight and the latest science, we can create lighting that makes life even better. Humans are made to be outdoors, and daylight affects the way we are – biologically and psychologically. New research has shed light on these links.
Read moreRelated News

Lighting the way: smart, sustainable, and science-backed illumination for tomorrow’s universities
As universities across the UK and beyond strive to modernise campuses, reduce emissions, and improve student well-being, one often-overlooked asset is proving to be a game changer: lighting. An active contributor to cognitive performance, energy efficiency, and the overall learning experience. Our recent projects, such as at the University of Warwick and Queen Mary University of London, demonstrate how forward-thinking institutions are embracing lighting as part of their strategic transformation. By adopting smart systems and biologically informed design, these universities are creating environments that not only look modern but also support academic success and sustainability. Smart lighting in action: The University of Warwick The University of Warwick’s recent library refurbishment offers a compelling case study in the power of intelligent lighting. By installing Fagerhult’s Organic Response system, the university achieved a 70% reduction in energy consumption, without compromising the quality of light. Organic Response uses sensors built directly into luminaires, enabling each fixture to respond individually to occupancy, ambient daylight, and usage patterns. This level of adaptability creates a consistently comfortable environment while dramatically reducing energy waste. The system also provides real-time occupancy data, allowing students to find available study areas more easily—an unexpected but impactful benefit. The Warwick project demonstrates how lighting can become a silent partner in campus operations: lowering costs, supporting carbon targets, and improving the day-to-day student experience. Lighting by biology: the role of melanopic lux Beyond energy and aesthetics, lighting plays a biological role, especially in education. Exposure to the right kind of light at the right time affects our circadian rhythms, alertness, and even mood. The concept of melanopic lux, a measure of how light impacts the body’s internal clock, has emerged as a critical consideration in educational lighting. The general recommendation is that students begin their day in environments with at least 250 melanopic lux for two hours. This aligns with natural biological rhythms, helping to boost concentration and support healthy sleep-wake cycles. This recommendation is grounded in international best practice, including the WELL Building Standard and chronobiological research such as the study published in PLOS Biology (2022), which outlines how morning exposure to at least 250 melanopic lux (also known as melanopic equivalent daylight illuminance) can significantly enhance cognitive function, mood regulation, and circadian rhythm alignment. Especially in educational settings, where mental clarity and alertness are critical, incorporating this biologically effective light level helps create environments that truly support both academic performance and student well-being. Smart, tunable lighting systems can shift light temperature and intensity throughout the day, mimicking natural daylight patterns. This kind of responsive design is especially powerful in windowless or high-use indoor areas like libraries, labs, or study zones. Queen Mary University: sustainability meets strategy Queen Mary University of London offers another example of lighting’s transformative potential. By integrating Organic Response technology into a major refurbishment, the university not only enhanced lighting performance but also achieved meaningful sustainability gains; cutting up to 75 tonnes of carbon dioxide emissions. In a sector under increasing pressure to meet environmental targets, lighting offers one of the most efficient paths to carbon reduction. Yet Queen Mary’s approach also shows that sustainability doesn’t mean compromise: the university improved user control, visual comfort, and building aesthetics in parallel with its environmental goals. This reflects a wider trend: universities are starting to view lighting upgrades not as maintenance, but as strategic infrastructure investments. Five Pillars of future-ready University lighting Drawing on Fagerhult’s experience in educational settings, five key pillars have emerged to guide universities as they plan for the future: Functionality: Lighting must support a range of learning styles, from silent reading to interactive group work. Flexibility: Modular lighting solutions accommodate evolving space usage and room layouts. Sustainability: Energy-efficient LEDs and daylight harvesting contribute to net-zero targets. Connectivity: Smart systems offer data-driven control and automation, improving both comfort and efficiency. Human-Centricity: Lighting should reflect human biological needs, enhancing comfort, alertness, and mental well-being. This framework helps institutions think beyond the “what” of lighting (lumens, watts) and focus on the “why” and “how”- how lighting contributes to learning outcomes, user satisfaction, and long-term adaptability. Lighting as an enabler, not just an asset As the education sector evolves shaped by hybrid learning, flexible campuses, and heightened awareness of student well-being; lighting is evolving with it. Once considered passive infrastructure, it is now recognised as an active enabler of performance, sustainability, and innovation. The message is clear: investing in modern lighting isn’t just about reducing bills or replacing old fittings. It’s about creating spaces that support people, helping students think more clearly, feel more comfortable, and succeed more fully. Fagerhult’s education projects continue to prove that the right lighting doesn’t just illuminate, it empowers. For universities aiming to future-proof their campuses, lighting is no longer optional. It’s essential.
Control Track Versa: empowering offices of the future with lasting flexibility
In 2024, the UK workplace landscape saw a gradual return to in-person work, with office attendance increasing to an average of three days per week, according to the Centre for Cities data. While major corporations such as Barclays and Lloyds Banking Group enforced stricter in-office policies, hybrid working remained a key factor in attracting and retaining talent, with nearly half of UK graduates unwilling to apply for roles without flexible options. This evolving work pattern is influencing office leasing trends, with new data from Re-Leased showing a shift toward longer lease agreements in both the office and retail sectors. In Q1 2024, the average UK office lease length increased by 27% to 3.7 years. Lease duration of three to five years surged by 69%. However, short-term flexible leases remain in demand. As businesses seek to optimise their space efficiency while balancing employee flexibility, rental offices must prioritise adaptable fit-outs that accommodate evolving tenant needs. These shifting lease dynamics also impact the lifecycle of office assets, including lighting. Traditionally, light fittings have had the capacity to operate for 20–25 years, which once aligned more closely with longer office lease terms. In the 1990s, leases in the UK office market typically ranged from 10–15 years, often with mid-term break clauses. Today, lease durations have shortened considerably, with many now averaging just 3–5 years — reflecting the rise of more agile and flexible workspace models. As a result, lighting systems are likely to change hands multiple times before reaching the end of their intended life. This raises an important question: how do we design and specify products built to last two decades for spaces that may be reconfigured, relet, or vacated in under five? Adapting to flexibility, health, and productivity To adapt to this new norm, office fit outs must be more flexible and sustainable. This is where the Control Track Versa comes in—a cutting-edge track lighting system that offers unparalleled versatility. It serves as its own infrastructure, allowing for a range of lighting combinations that can easily be adapted to different tenant needs and office layouts, making it an ideal solution for modern, flexible workspaces. A creative edge This suspended track system offers exceptional flexibility in lighting design. It features a dual track known as Control Track Dual which supports direct, indirect, and intermediate configurations and is compatible with luminaires using a Eurostandard+ adapter, ensuring broad usability. Notable compatible products include the VIL Luminaire, designed for dual Control Track use, providing seamless uplight with 300 lux at the ceiling and various lumen output options. The Pleiad G4 128 Track offers advanced solutions for modern offices, while the Zkye 55 G2 Zoom Spotlight adds precision and flexibility for adjustable focus. The Notor 65 Track integrates effortlessly with the system, delivering efficient lighting, and with Integrated Organic Response Sensor enhances energy savings with smart technology. These luminaires demonstrate the system’s adaptability, catering to diverse needs across a range of different spaces. Control Track Versa allows seamless integration of track and luminaires, creating visually appealing setups suited to both minimalist and extravagant styles. By employing lighting principles like focal glow (highlighting specific areas), ambient luminescence (soft overall brightness), and the play of brilliance (creating contrast and depth), designers can craft dynamic and engaging spaces. Ideal for commercial and office workspaces, providing the tools for stunning and effective lighting solutions. Organic response for a long-term infrastructure Control Track Versa offers an adaptable lighting system, ideal for sustainable, forward-thinking projects. Built on a 230V setup, it integrates with advanced lighting control systems, like Organic Response. This wireless Plug & Play solution, designed for workplaces and learning environments, features luminaires with presence sensors that activate upon connection to mains, removing the need for complex programming. Organic Response automatically adjusts lighting based on occupancy, optimising energy use. As each luminaire has its own driver it simplifies rearrangements without the need to recalculate capacity, a common challenge in traditional 48V systems. The design also minimises installation issues, creating a cleaner aesthetic. Control Track Versa, with Organic Response, provides dynamic lighting that adapts as workspace needs change. Flexible lighting designs, planned from the outset, support evolving tenant requirements without compromising energy efficiency or sustainability. As workplaces become more dynamic, lighting quality can be significantly enhanced to meet the needs of modern, tenant-focused spaces. Simplicity that offers versatility The adaptability of both the tracks and fixtures ensures that Control Track Versa can meet the demands of tenants and clients alike. Recognising the collaborative nature of today’s workplaces, this range has been expanded with various track-mounted products designed to accommodate the evolving needs of modern offices. As office spaces become more dynamic, the challenges of short-term leases and temporary spaces are significantly mitigated, making Control Track Versa the perfect solution for fast-paced, ever-changing environments. If you’re curious to see more of what the Control Track versa is capable of, see the full product page or for all products visit our website.