International Commission On Illumination

The International Commission on Illumination, known by its French title Commission internationale de l’éclairage (CIE), is the leading global authority on light, lighting, colour and colour spaces. Founded in 1913 as the successor to the Commission Internationale de Photométrie established in 1900, the CIE has played a pivotal role in developing internationally recognised standards and models for colour measurement, vision science and lighting technology. Its work underpins modern colourimetry and has shaped scientific, industrial and technological practices in imaging, lighting design and visual perception. The organisation is headquartered in Vienna.

Organisation and Structure

The CIE operates through specialised divisions, each responsible for a distinct area of research and standardisation. These divisions establish technical committees that focus on developing guidance, terminology, measurement principles and international standards.
The six active divisions are:

• Division 1: Vision and Colour – concerned with visual perception, colour science and models of colour appearance.
• Division 2: Physical Measurement of Light and Radiation – addresses methods for quantifying optical radiation and photometric units.
• Division 3: Interior Environment and Lighting Design – develops standards and best practices for interior lighting, including ergonomics and visual comfort.
• Division 4: Transportation and Exterior Applications – focuses on lighting for roads, vehicles, urban environments and outdoor applications.
• Division 6: Photobiology and Photochemistry – examines biological and chemical effects of light exposure.
• Division 8: Image Technology – covers colour reproduction, imaging systems, displays and digital workflows.

Two earlier divisions are no longer active: Division 5 (Exterior Lighting and Other Applications) and Division 7 (General Aspects of Lighting). Since 2023, the organisation has been led by its President, Jennifer Veitch of Canada.
The CIE publishes a wide range of documents, including Technical Reports (TRs), International Standards (ISs) and Technical Notes (TNs). Many standards are later harmonised with the International Organization for Standardization (ISO) or the International Electrotechnical Commission (IEC), reinforcing their global applicability.

Major Milestones in Colour Science

The CIE’s contributions to colour science are foundational. Key milestones include:

• 1924 – CIE Standard Observer (Photopic Vision): introduction of the CIE 1931 colour space based on the spectral luminous efficiency function V(λ), defining human visual response under well-lit conditions.
• 1951 – Scotopic Standard Observer: establishment of the V′(λ) function to model visual sensitivity under low-light (scotopic) conditions.
• 1964 – 10° Standard Observer and Daylight Illuminants: definition of the 10-degree observer with revised colour-matching functions to better represent human colour perception across a wider field of view. Standard daylight illuminant D65, representing daylight at ~6500 K, was added alongside methods for deriving daylight illuminants at other correlated colour temperatures.
• 1976 – Development of Uniform Colour Spaces: introduction of CIELAB and CIELUV, which provide approximately perceptually uniform colour spaces. These models remain widely used in colour specification, calibration and quality control across industries.
• 1990s–2000s – Colour Difference Formula Refinements: publication of updated colour difference metrics including CIEDE94 and CIEDE2000, improving correlation with human perception for applications in printing, manufacturing and digital imaging.

These standards and models form the foundation of modern colour measurement and are used across fields such as spectrophotometry, industrial colour matching, display calibration and visual ergonomics.

Scientific and Technical Contributions

Beyond colour science, the CIE contributes significantly to broader areas of lighting and optical technology. Examples include:

• establishing consistent terminology and measurement protocols for lighting design;
• developing guidelines for photobiological safety;
• supporting research into circadian effects of light;
• providing technical bases for imaging systems, including digital colour management;
• offering frameworks used in transportation lighting, including vehicle headlamps and road illumination.