CIE Division 1 and Division 2 organized jointly with the Hungarian National Committee of the CIE a symposium on questions of light and colour perception and measurement that are still debated internationally.

The meeting was divided into five main sessions:

•Perception and Flashing Lights
•Physical Photometry and Colorimetry
•Mesopic Photometry
•Contrast Sensitivity
•Spatial-Colour Perception and Measurements
and included a Poster Session of post-deadline papers. The Proceedings contains the edited versions of the 24 papers presented.

Each main section of the Proceedings starts with an Invited Paper, so that also persons who are not experts in the field can get an overview on the questions that are debated, both related to perception and measurement of lights changing in time and/or place. The Contributed Papers go then into detail, explaining where still further research is needed - and partially also offering solutions on these open questions.

This Proceedings should be on the desk of everybody who would like to get an insight on fundamental research going on in the field of flashing lights, perception and measurement of light and colour changing also in their spatial distribution.