Sunlight & Health
The light you evolved under still shapes your health.
We’ve spent our lives indoors, under lighting designed only for our eyes. Physicists, doctors and circadian scientists are now showing how much the rest of the body depends on daylight, from the energy in our cells to our mood and sleep. This is what they’ve found, and what you can do about it.
~50%
of the Sun’s energy reaches us as invisible infrared light
90%
of our time is now spent indoors, away from daylight
88,000
people studied to link bright days and dark nights with lower depression risk
EXPLORE THE TOPICS
Six ways light shapes your health
Each guide brings together the research and the voices from our Sunlight Matters podcast, with practical steps you can take today.
Light & your cells
How infrared light from the sun helps the energy factories in your cells run more smoothly.
Read the guide →
Light & mood
Why bright days and dark nights are linked to a lower risk of depression.
Read the guide →
Body clock & sleep
How morning light, dark evenings and a strong daily rhythm keep your body in sync.
Read the guide →
Sun, skin & safety
What the research says about melanin, building up exposure gradually and never burning.
Read the guide →
Indoor light
How LEDs and modern glazing changed the light we live under, and what you can do about it.
Read the guide →
Seasons & latitude
Why northern winters take a toll, and how to make the most of the light you have.
Read the guide →
YOUR DAILY SUN GUIDE
Small habits, every day
Morning
Get outside within an hour of waking. Morning light helps set your body clock for the day ahead.
Daytime
All daylight counts. Step out at lunch, roll up your sleeves and spend time near trees and greenery.
Evening
Keep light dim and warm after sunset, and move bright screens and overhead lights away from bedtime.
Winter
Make the most of short days, and when summer comes, build up your time in the sun gradually so you never burn.
“Mitochondria are very, very tuned to daylight, and you can’t really fool them.”
Prof. Glen Jeffery, UCL Institute of Ophthalmology
Where this comes from
Built on research and real conversations
Every guide draws on published research and on interviews from our Sunlight Matters podcast with physicists, doctors and circadian scientists. We link to our sources so you can explore them yourself.
Put it into practice
Find your sun with Shadowmap
See exactly when sunlight reaches your home, your garden or the nearest spot to watch the sunrise, on any day of the year.
The information on these pages is for general education and is not medical advice. Speak to a doctor about your own health.
