I report on the opening ceremony of the International Year of Light and Light-based Technologies
2015 (IYL2015), which took place at the UNESCO headquarters in Paris, France, on 19–20 January 2015.
Over the two days, more than 1000 participants from all over the world learned more about the
fundamental properties of light and advanced photonics applications, the history of optics and its
applications through the centuries, light poverty and light pollution, and light for everyday life,
health and research.