CIE Position Statement on Integrative Lighting Recommending Proper Light at the Proper Time

Knowledge about the effects of light on human health, behaviour, and well-being is advancing rapidly, as is interest in applying this knowledge in lighting technologies and practice. This CIE Position Statement is the third edition on this topic, updating its 2019 predecessor to incorporate the recommendations from the Second International Workshop on Circadian and Neurophysiological Photoreception (held in Manchester, UK, in 2019). Following the 2024 publication of a CIE Technical Note documenting the workshop deliberations, this Position Statement summarizes the workshop recommendations and outlines further questions that remain before these can be fully integrated into general lighting recommendations. The CIE Position Statement reaffirms that research and application intended to consider integrative lighting should incorporate the CIE system for metrology of ipRGC-influenced effects of light (CIE S 026:2018). Finally, this updated CIE Position Statement concludes with a commitment to join an international effort to develop communications for the general public to inform individuals about how to use the currently-available knowledge about light and darkness for their personal health and well-being. Key take-away points from this Position Statement are: Good lighting quality balances human well-being, health, and functioning to achieve integrative lighting, while also respecting energy, environmental, and architectural considerations. Characterizing light for integrative effects should follow CIE S 026:2018, CIE System for Metrology of Optical Radiation for ipRGC-Influenced Responses to Light. International experts meeting in Manchester, UK, proposed guidance for a healthy pattern of daily light exposure for healthy young adults that recommends a high light exposure during the day, a much lower level for 3 hours before bed, and near-darkness during sleep. Applying these recommendations in order to deliver high-quality integrative lighting will require careful design attention to prevent glare and manage lighting energy use, among other considerations. Enough is known today about lighting for health to provide general guidance to the public, which the CIE will provide together with other international partners in the coming months