10 years ago, UNESCO launched the International Year of Light and Light-based Technologies – a year-long celebration of light and its impact on human society, that spawned a number of lighting events, including the very first [d]arc awards. 10 years later, we look back on its impact and its legacy.

In 2015, something extraordinary happened. Under the patronage of UNESCO and adopted by the United Nations, the International Year of Light and Light-based Technologies (IYL 2015) launched a global celebration of light – its science, its applications, and its profound importance to human society. What started as a science-led initiative quickly evolved into something broader and more inclusive, thanks to the passion and persistence of the lighting design community, and the support of UNESCO. Ten years later, as arc magazine celebrates the newest winners of the [d]arc awards – a programme born from that very same momentum – we pause to reflect on how IYL 2015 changed the course of lighting design history.

The Origins

The first idea for an International Year of Light dates back to 2009, when IYL 2015 Steering Committee Chair John Dudley proposed the ideal while representing the Quantum Electronics and Optics Division (QEOD) of the European Physical Society (EPS) at a meeting of the International Council of Quantum Electronics (ICQE) in Baltimore, USA. An item that was discussed at this meeting was how to follow up activities that were planned to celebrate the 50^th anniversary of the laser in 2010 with something even more ambitious. The photonics community felt that there was an opportunity to reach out beyond the scientific sector to raise much broader awareness of the problem-solving potential of light-based science in so many areas of life, and to make a global effort to influence education and policy in both developed and developing countries. The proposal was endorsed by ICQE, which then began the path towards IYL 2015.

International Years are part of the United Nations declared observances, designed to promote awareness of issues relevant to its aims and international programmes. The first step to successfully achieve the proclamation of the International Year is to work through UNESCO to prepare and submit a resolution to the UN General Assembly; but before this, EPS had to construct the proposal in detail, and build a consortium amongst the major optics and physics societies. During 2010 and 2011, the main motivations and goals for IYL 2015 were drafted, and it was decided that 2015 would be the target year, based on several key scientific anniversaries.

Reflecting on these initial conversations, John Dudley tells arc: “It was extremely difficult to learn how to interact within the UN system. Luckily, we were helped by Ana Maria Cetto from Mexico, who had extensive previous experience with UNESCO and the UN, as well as the late Professor Francis Allotey from Ghana. With their help, we were able to cross the starting line to launch the political process with a draft resolution to UNESCO. Once the resolution was adopted at UNESCO in 2012 in Paris, it opened the door to visiting New York and speaking at UN Headquarters in 2013. [The date of this meeting was 16 May 2013 – the day that, coincidentally, became the UNESCO International Day of Light] A number of member states then took up the process, and a formal proclamation was made at the UN General Assembly in December 2013.”

With the official UN green light, work accelerated during 2014 to put into place all the structures to ensure the success of the year – fundraising, enhancing the network of organisations supporting the initiative, increasing the number of IYL National Nodes, and reaching out to non-scientific communities such as artists and architects.

In the UN’s Executive Summary of IYL 2015, published in July of 2016, an official statement defined the primary objectives of the year as follows: “The International Year afforded an unparalleled opportunity to demonstrate the importance of light science and its applications in contributing to the 2030 Agenda for Sustainable Development. In particular, light-based technologies contribute directly to the effective achievement of the Sustainable Development Goals, given that they provide practical and cost-effective solutions to challenges in areas such as agriculture and food science, energy and the environment, poverty eradication, water purification, combating diseases and climate change. Moreover, light science is an inspiring subject to stimulate children’s interest in education, and industries based on photonics are major economic drivers.

“A central aim of the International Year was to raise global awareness of the importance of those issues, and to stimulate associated capacity-building and research in the basic sciences and engineering. It also promoted the themes of visual arts and culture, architecture, and light pollution.”

From the Shadows into the Spotlight

However, when IYL 2015 was first proposed, lighting design wasn’t part of the conversation. The focus was firmly on photonics, optical technologies, and scientific breakthroughs. But lighting designers knew that light was more than data and devices.

A grassroots petition emerged, gathering momentum to include lighting design within IYL’s framework. Thanks to the excellent organisation of the IYL2015 Global Secretariat, and particularly to the welcoming support of ICTP, UNESCO Category I Institute, the outcome transformed the initiative itself: lighting design wasn’t merely recognised – it became integral to IYL’s identity, illuminating light’s artistic, cultural, and social dimensions alongside its scientific achievements.

Recalling the extra support that the lighting design community brought to IYL 2015, Dudley adds: “Aspects of public lighting quality, culture, and design were essential in reaching the general public. UNESCO has three key words in the acronym: education, science, culture. But experience shows it’s much easier to attract people to an education/science event if there is a light show that showcases art, design, and broader themes.”

It was in this context that the Lighting-Related Organisations (L-RO) coalition was born: a voluntary federation of 45 international associations, institutions, the academic world and media (including arc magazine), formed to ensure the built environment and human experience were part of the global light conversation.

Soon after, the International Association of Lighting Designers (IALD), a founding L-RO member, became a patron sponsor of IYL2015, underscoring its commitment to promoting the power and potential of light on a global stage. IALD’s sponsorship and active involvement were crucial in elevating the visibility and importance of architectural lighting design within the broader celebration of light during IYL 2015, particularly highlighting its relevance to the built environment and human wellbeing.

The Emotion-driven Technology

Lighting designers brought something to IYL 2015 that no one else could: a unique blend of science, art, and empathy. As Joe Niemela, Global Coordinator for IYL 2015 at UNESCO, stated in an interview for issue 82 of arc magazine (then known as mondo*arc), “I think the role of Lighting Designers should be… BIG.” Designers showed how light isn’t just functional – it’s emotional. It shapes behaviour, fosters connection, creates identity, and uplifts communities.

The IYL platform made it possible for the wider world to see what designers had long understood: that light can help make a street feel safe, a home feel warm, or a public space feel magical. Through exhibitions, educational events, public interventions, and artistic installations, lighting designers around the world illuminated the human and space experience of light. Meanwhile, education-based events were held worldwide demonstrating the physics and magic of light for students, professionals, and citizens alike.

Amongst the many events launched to coincide with IYL 2015 (of which Dudley believes there were “more than 13,000”), UNESCO held an official Opening Ceremony on 19-20 January 2015 in Paris, France, whose 55 speakers included UNESCO leaders, five Nobel laureates, distinguished international scientists, students, representatives of non-governmental organisations, former CEO of Signify, Eric Rondolat, and then-IALD President, Barbara Horton. A closing ceremony was held in Mérida, Mexico, from 4-6 February 2016, in which follow-up actions were defined for the future. The ceremony was accompanied by art events, a high school outreach programme, a film festival, and a light installation at the archaeological site of Chichén Itzá.

Several countries obtained high-level support and patronage from Heads of Stage, while several governments officially recognized the International Year. Many countries chose light as the theme for important national science education initiatives, while regionally, the European Commission provided €2.65million for coordination and support in 30 European countries to promote the importance of light science and careers in photonics to young people, entrepreneurs, and the general public. It is this involvement in education that Dudley recalls the most fondly. He said: “Personally, I really liked the events I was involved in at schools – seeing the enthusiasm of young people for light was remarkable. 10 years later, I am regularly contacted by people who participated in outreach events in schools during 2015, and who are now continuing the legacy in their own careers.”

Reflecting on IYL 2015 10 years later, Joe Niemela recalls how the diversity of lighting as both a concept and a profession added to this broad array of lighting events: “The term ‘light’ attracted many different and important segments of society. For instance, light artists were very active during the year, as were the lighting community, in terms of improved living and working spaces, spectral tuning of digital lighting sources for wellbeing and productivity and affordable and accessible lighting in the many parts of the globe that lack it, thereby providing light that enhances education and also safety.

“Then there were elements of light as a philosophical concept (enlightenment, knowledge, etc), which reached directly to cross-sectoral aspects of UNESCO and also attracted, for example, the Vatican (which produced its own commemorative postage stamp), and of course, the optics and photonics community providing, amongst other things, applications of affordable technology to aid in food production, water purification, healthcare, and more throughout the developing and developed world. This diversity in partners mirrored the diversity of our societies, reflecting the need to work together for sustainable solutions to pressing societal challenges. Raising awareness of the potential of light and light-based technologies to improve our quality of life – across a broad spectrum of society – was directly connected to the overall success of the year.”

L-RO members and countless volunteers donated their time, energy, and expertise throughout the year. This collective effort – driven by commitment, passion, and professionalism – fostered a global community united by light’s potential. Their dedication transformed IYL 2015 from celebration into movement, creating ripples that continue expanding today.

Lighting a Legacy

The L-RO’s final publication, We Are Light, captured the spirit of this transformation. The IALD supported this initiative, printing the booklet as a great effort of cooperation and advocacy. We Are Light presented the activities organised by L-RO to celebrate the Year of Light, and emphasised on expanding the knowledge of lighting beyond the profession, planting the seeds for cross-disciplinary thinking that continues to flourish today.

And while the International Year of Light officially ended, its energy lives on in lighting festivals, academic programmes, social impact projects, and design communities. It lives on in the [d]arc awards, which launched as an official IYL 2015 activity and has since become a defining platform for contemporary lighting design. It lives on in the countless collaborations sparked during that year, many of which still shine brightly.

The legacy of IYL 2015 is one of recognition and relevance. A decade ago, lighting design was often dismissed as niche or luxury. Today, it’s increasingly recognised as essential – an agent of sustainability, wellbeing, and cultural enrichment that shapes how we experience the world around us.

Reflecting on the impact of IYL 2015, Dudley adds: “There have been a number of important outcomes at different levels. Firstly, when we started working with UNESCO in 2012, the value of International Years as an instrument for education and awareness raising was being discussed and evaluated within the UN system, and the success of 2015 really helped to cement their place. In fact, Joe was present in New York in 2016 in a special session where the final report was presented to the UN General Assembly.

“We used the 2015 experience to help other groups with their international year projects as well: the International Year of the Periodic Table of Elements (2019); the International Year of Glass (2022); the International Year of Basic Science for Sustainable Development (2022-23); the International Year of Quantum Science and Technology (2025). I think we really made life a lot easier for them, as they were able to point to what a real successful international outreach initiative can achieve.

“And, of course, the International Day of Light is a direct legacy, which is now celebrated annually – in the eight editions so far, we have seen over 3,000 events worldwide in more than 100 countries, continuing to reach out to new audiences, and new generations of young people.”

The Next Ten Years

The challenges we face, climate change, urban transformation, biodiversity loss, require new ways of thinking. Lighting design, with its unique ability to blend technology and empathy, form and function, is poised to help lead that charge.

As the lights go up on this year’s [d]arc awards winners, it’s worth remembering that their platform was built not just from accolades, but from advocacy. Their spotlight exists because a community of designers believed in the value of what they do, and demanded to be seen.

As we look ahead, the legacy of IYL 2015 reminds us of what’s possible when lighting designers claim their space in the global dialogue, not just as technicians, but as storytellers, changemakers, and stewards of light.

Ten years ago, we proved that light could unite us. Now, it’s time to let it guide us forward, on a shared mission: “With the people, for the people, through Light.”