The power of light to change your world for good

Professor Steven Lockley

About Professor Lockley

Professor Steven Lockley heads up the Circadian Physiology Program at Harvard University.

This focuses on basic and applied aspects of human circadian biology.

His translational approach includes use of a range of techniques including epidemiology, field-based physiological studies and inpatient intensive physiological monitoring. They have a particular interest in human circadian photoreception and the effects of light on the circadian pacemaker and other non-image forming responses.

Their studies include investigations of the effects of timing, duration, intensity and wavelength of light exposure on circadian resetting, melatonin suppression and the acute alerting effects of light. They also study visually impaired individuals under field and laboratory conditions to examine the effects of the severity and type of blindness on circadian photoreception, the periodicity of the circadian pacemaker and development of circadian rhythm sleep disorders. These basic studies have led to the development of novel therapeutic strategies to treat non-24-hour sleep wake disorder, Advanced- and Delayed Sleep Phase Syndrome with appropriately-timed melatonin administration in blind patients. They have also recently begun to examine the role of visual impairment on endocrinology and breast cancer risk in blind women.

​With the Harvard Work Hours Health and Safety Group, they assess the impact of extended work hours on health and safety of workers and the public. Their studies include the development of interventions that reduce extended duration work hours, fatigue and medical errors in hospital residents, and the implementation of large-scale occupational fatigue management and sleep disorders screening programs in several police forces nationwide.

For more information about Professor Steven Lockley’s ground-breaking research into light and sleep, please go to

Harvard University Graduate School of Design, Executive Education

And at the University of Surrey 

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