Report on the First International Workshop on Circadian and Neurophysiological Photometry, 2013

CIE TN 003:2015
Division 6

This Technical Note deals with the role of the eye in processing light information and the measurement of the eye’s light exposure, with particular emphasis on the physiological or photobiological effects whose distinction from visual perception has become widely recognized since the discovery of melanopsin in human retinal ganglion cells. The Technical Note summarizes the proceedings and consensus of The 1st International Workshop on Circadian and Neurophysiological Photometry (“IWCNP 2013”, the “Workshop”) and aims to provide an interpretation for governments, the lighting community and professionals working in public health, and to highlight the importance of scientific advances and the growing evidence base in this area.
On 28 February 2013 a report was formally requested by Division 6 of the CIE, to summarize the views of an independent scientific workshop of international experts in the fields of circadian and neurophysiological photoreception, primarily composed of non-lighting specialists, for whose work the measurement of light has become an important issue. The role of rapporteur was offered to and accepted by Luke L.A. Price, GB.
The reportership was originally charged with producing a report to the CIE, which the CIE would issue as a free downloadable electronic publication. The CIE felt that an independent workshop would provide a step towards future measurement standards related to the non-visual effects of light on health. However, as some of the IWCNP recommendations might be mistaken for CIE recommendations or even standards, and as in some places these do not comply with the SI system, which the CIE supports, the scope of the reportership was modified.
The intention of these changes are that this Technical Note shall replace the need for the report originally requested, and include CIE comments related to its own measurement recommendations. This publication is available as a freely downloadable electronic document, together with an SI-compliant version of the Workshop’s toolbox (downloadable at, which it is hoped will support researchers in expressing their measurements as SI quantities and in SI units.
It is important to appreciate that the difference between the Workshop and CIE recommendations relates solely to the description of quantities and units, and not their underlying nature. Every care has been taken to ensure the reader can easily distinguish between the IWCNP and CIE systems. The CIE is prepared to support the Workshop consensus provided compliant SI units are adopted.
The publication is written in English, consists of 39 pages and is freely downloadable from the CIE website.

The following member of DR 6-42 “Report on the 1st International Workshop for Action Spectra of Non Image Forming Photobiological Effects of Light” took part in the preparation of this Technical Note:

  • Price, L.L.A. Public Health England, Didcot, United Kingdom (CIE Division 6 Secretary)

The following international scientific experts are advisers relating to this report:

  • Lucas, R.J. University of Manchester, United Kingdom (Workshop co-chair; CEN TC 169/WG 13)
  • Brainard, G.C. Thomas Jefferson University, Philadelphia, PA, USA (Workshop co-chair)
  • Berson, D.M. Brown University, Providence, USA
  • Brown, T .M. University of Manchester, United Kingdom
  • Cooper, H.M. Stem-cell and Brain Research Institute, Lyon, France
  • Czeisler, C.A. Brigham and Women's Hospital and Harvard Medical School, Boston, USA
  • Figueiro, M.G. Lighting Research Center, Rensselaer Polytechnic Institute, Troy, NY, USA
  • Gamlin, P.D. University of Alabama at Birmingham, Birmingham, AL, USA
  • Lockley, S.W. Brigham and Women's Hospital and Harvard Medical School, Boston, USA
  • O’Hagan, J.B. Public Health England, Didcot, United Kingdom (CIE Division 6 Director; CEN TC 169/WG 13)
  • Peirson, S.N. University of Oxford, United Kingdom
  • Provencio, I. University of Virginia, Charlottesville, VA, USA
  • Skene, D.J. University of Surrey, Guildford, United Kingdom

All fourteen of the above took part in The 1st International Workshop on Circadian and Neurophysiological Photometry, 2013. Selected roles within the workshop and related standard setting bodies are listed.
S.N. Peirson and L.L.A. Price have developed the toolbox for calculation and conversions between units for light measurements on behalf of the workshop, with notable assistance from R.J. Lucas, T.M. Brown, G.C. Brainard and his colleagues B. Warfield and J.P. Hanifin at Thomas Jefferson University, and K. Baczynska of Public Health England.