Quality of Light (Performance & Wellbeing)

Quality of Light (Performance & Wellbeing)


Quality of light describes the aspects of light that impact productivity, performance, comfort, aesthetics, mood, safety, health, and wellbeing. Lighting that provides comfortable, safe environments for people is critical, leading to wider adoption and persistent energy savings. The DLC is providing information about the quality of light properties of listed products in its proposed Technical Requirements V5.0 for the following topics: 

  • Color Quality
    Color quality refers to two performance aspects of light: the color of light emitted by a product (chromaticity) and the color of the objects illuminated by that light (color rendering). Poor color quality can be associated with negative effects, ranging from a decrease in comfort and wellbeing, to potentially dangerous impacts due to errors in judgment or color discrimination.
  • Flicker
    Flicker describes fluctuations in light output of a fixture over time. SSL products with poor flicker performance carry potential health and safety impacts, such as lowered visibility, headaches, eyestrain, or simple annoyance. Flicker-free operation is fundamental for safe and comfortable lighting.
  • Glare
    LED products with good optical design and glare control will shield the eye from the exposure to high-contrast, bright light. Low-glare design supports task performance, comfort and safety, and prevents glare-related headaches and eyestrain. With good, high-quality optical design, energy efficiency and glare control do not need to be mutually exclusive.
  • Lighting for Alertness and Circadian Wellbeing
    Lighting for alertness and circadian wellbeing refers to the ability of light to impact performance, mood, and daily (circadian) biological rhythms. While many additional environmental factors also play a role in modulating these cycles, the fact remains that today, people spend most of their time indoors under various electrical lighting conditions. Lighting solutions that consider the effects of light on human alertness and biological rhythms can support healthy and safe environments for all.
  • Optical Distribution
    For comfortable and safe working and living environments, light should be effectively directed to the areas where illumination is desired and/or needed. The direction and distribution of light can be customized using several methods of optical design, such as lenses, refractors, reflectors, louvers, or baffles. Luminaires that fail to provide good optical control do not direct light where it is needed, wasting energy and creating unwanted light spill (e.g. light trespass and sky glow).


Improve the quality of light in the built environment, helping to ensure safe, comfortable, and productive settings for people, mitigating negative impacts of electrical light, and realizing lasting energy savings. 


Desired Outcomes:


Adoption of high efficiency SSL products with superior quality of light performance for their specific application increases.


Lighting decision makers have the tools and information they need to be able to identify high performing products for applications where quality of light is important.

Utilities are able to better identify and promote products that save more energy and deliver better quality of light, resulting in more comfortable and safe environments for their customers.