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Committee on the Environment

  • COST

    Free and open to the public

  • TYPE

    Knowledge Community



The Right Light at the Right Time: Redesigning light for alertness, sleep and health

The newly-discovered relationships of light to the health and productivity of building occupants presents architects, owners, lighting engineers and developers with new and exciting opportunities.

Much as the ear has two functions in controlling hearing and balance, the eye has dual roles in detecting light to allow us to see, and to stimulate a number of non-visual effects of light including resetting the circadian clock, suppressing the pineal hormone melatonin, and directing alerting the brain. These visual and non-visual effects of light utilize functionally and anatomically distinct photoreception systems, including different photoreceptors – rod and cones primarily for vision, and the blue-light sensitive photopigment melanopsin primarily for non-visual responses, although there is some overlap.

The independence of these two systems means that light properties, including intensity, spectrum, and pattern, can be manipulated to differentially stimulate either, or both, sets of responses. In practice, lighting should be designed to optimize both visual and non-visual effects and this can be achieved by using tunable lighting systems that can vary the spectrum, intensity and timing of light output. LED lighting now makes such changes possible, practical and potentially cost-neutral given the energy efficiency gained when replacing non-LED sources.

Join Steven W. Lockley, PhD as he provides an overview of how and why light is an important contributor to occupants’ alertness, health, and productivity and show examples of environments that have benefited from this approach including schools, care homes, offices and the International Space Station.

Steven W. Lockley, PhD
Neuroscientist, Brigham and Women’s Hospital
Associate Professor of Medicine, Harvard Medical School

For those who qualify, 2 LU/HSWs are available.

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