On darker days the atmosphere filters out a significant portion of this light spectrum. While you still receive some light, the intensity is insufficient to fully suppress daytime sleepiness or optimise serotonin production.
On bright days, direct sunlight hits the retina and triggers the release of serotonin. This sharpens focus, elevates mood and sets a timer for the evening release of melatonin, ensuring deeper sleep.
Transmits light data directly to the body’s master clock to maintain natural rhythms.
Converts light into precise timing signals that govern daily rest and activity patterns.
Regulates the essential release of hormones throughout the body.
Boosts alertness and optimizes metabolic function for peak daily health.
Studied at Harvard Medical School and written over 160 papers. Located the suprachiasmatic nucleus.
View full profile
Over 25 years in the lighting industry with the UK's No.1 KBB lighting brand. Established Bio-Labs from Bio-Medical research with Leeds University.
View full profile
Launched Freeserve (UK's first mass-market ISP). Former CCO Bristan Group. VP Bathroom Manufacturers Association.
View full profile
Chartered Engineer and lighting specialist with over 40 years of experience across research, innovation and industry leadership.
View full profile
Eight hours. It's the number that's been baked into every sleep guideline, wellness app, and bedtime reminder for decades. But the science is more nuanced than that — and understanding it could change how you approach one of the most important things you do every day.
The phrase “human-centric lighting” appears in nearly every major commercial specification today. Architects know it. Facilities managers have heard it. But most buildings that claim to deliver it are falling short of what the science actually requires.
Tunable white lighting has become the default answer when a client asks for human-centric or circadian-responsive design. Specify it, programme a schedule, job done. Except it isn't.
