for a healthier and happier life
What is good light
Good light is the right light at the right time in accordance with our activity and our personal needs during each day of our lives. Good light is natural light, or indoor light that mimics natural light as much as possible.
Good light is attractive
Good light indoors is high quality and comfortable for the eyes.
High quality means that the lighting system provides good colours (rendering and preference), low glare, no temporal light artifacts (flicker and stroboscopic effects), attractive contrast differences and distribution of light in the environment, no audible noise and being safe.
Good light is dynamic
Good light indoors is stimulating during the day with an intensity that is at least 5x higher and relaxing during the evening with an intensity that is at least 5x lower, than the current standard for vision.
With aging, from 50 years onwards, higher intensities are usually needed to support visual and non-visual needs. In case of shiftwork or work in evening/night or work at irregular times, deviations from these guidelines are needed. Horizontal and vertical light levels need to be adequate for both visual and non-visual effects.
Good light is optimized
Good light indoors has spectral characteristics that vary according to time of day, personal needs, and specific tasks.
In the morning and during daytime, the light spectrum should include a reasonable portion of short wavelengths to support the energizing and revitalizing effects of light. In the evening and at night, the amount of short wavelengths should be diminished to support winding down, a good night of sleep and to prevent disruptions of the day-night rhythm. With aging, from 50 years onwards, the need for spectral characteristics may change because of a change in lens characteristics. In case of shiftwork or work in evening/night or work at irregular times, deviations from these guidelines are needed.
Good light is personal
Good light indoors can be adapted by the user for personal needs based on suggestions by the system. Individuals may differ in light appreciation with respect to intensities and preference for warm or cool white light. In addition, individuals differ in the phase of their sleep-wake rhythm, also referred to as being a different chronotype. This results in individual differences in the most optimal timing of the dynamic pattern of light, both with respect to intensity and spectral characteristics. Personal control over the dynamics and spectral characteristics of light is highly appreciated by individuals.