The study of light has led to promising alternative energy sources, lifesaving medical advances in diagnostics technology and treatments, light-speed internet and many other discoveries that have revolutionized society and shaped our understanding of the universe. These technologies were developed through centuries of fundamental research on the properties of light – starting with Ibn Al-Haytham’s seminal work, Kitab al-Manazir (Book of Optics), published in 1015 and including Einstein’s work at the beginning of the 20th century, which changed the way we think about time and light.

Asia's First Sustainable Light Art Festival at Marina Bay - Singapore

Without light, our planet would be but a cold and barren place. Indeed, where there is light, there is often an abundance of life. Yet light represents even more for humanity. Light goes hand in hand with knowledge; it is a lens through which to see and understand the world.

UNESCO Director-General
Audrey AzoulayUNESCO Director-General
Message from Ms Audrey Azoulay, Director-General of UNESCO, on the occasion of International Day of Light
16 May 2023
UNESCO
0000385368

The International Day of Light celebrates the role light plays in science, culture and art, education, and sustainable development, and in fields as diverse as medicine, communications, and energy. The celebration will allow many different sectors of society worldwide to participate in activities that demonstrates how science, technology, art and culture can help achieve the goals of UNESCO – building the foundation for peaceful societies.

Why light matters

Light and Development
Light, Science and Technology
Light, Education and Culture

The message of the International Day of Light 2021 — Trust Science — encourages both scientists and the public alike to sign and support a declaration affirming their trust in science and the importance of public confidence in the scientific process. Now is the time for us all to pledge our support.

We ask all supporters of the International Day of Light and its objectives to join with us in signing the Trust Science Pledge. This includes those who support the crucial role of the scientific process in improving our quality of life.