Why Morning Sunlight May Be One of the Best Things You Can Do for Your Eyes and Body
What if one of the simplest ways to support better sleep, daytime alertness and your body’s internal clock was already sitting outside your front door?
No supplement. No complicated morning routine. No expensive wellness gadget.
Just daylight.
Getting outside for some natural light shortly after waking is a simple habit that has received increasing attention from sleep researchers, neuroscientists and health educators, including neuroscientist Dr. Andrew Huberman of Huberman Lab.
But why does something as ordinary as morning sunlight matter so much?
The answer starts with your eyes.
Your eyes do much more than help you see
Most people think of the eyes as cameras. They collect information about the world and send it to the brain so we can see.
But the eyes also contain specialized light-sensitive cells that help regulate the body's internal clock.
These cells, called intrinsically photosensitive retinal ganglion cells, or ipRGCs, contain a light-sensitive pigment called melanopsin. They respond particularly strongly to bright environmental light and communicate with a part of the brain called the suprachiasmatic nucleus, which acts as the body's central circadian clock. (PubMed)
In simple terms, your eyes are helping your brain answer one very important question:
"What time of day is it?"
And morning daylight is one of the strongest signals available.
Morning light helps set your circadian rhythm
Your circadian rhythm is your body's roughly 24-hour biological timing system.
It influences much more than when you feel sleepy. It helps coordinate daily patterns involving sleep, wakefulness, hormone release, body temperature and other biological processes.
Think of it as your body's master schedule.
The problem is that modern life can make that schedule a little confused.
We wake up inside a dark bedroom.
We turn on indoor lights.
We immediately check our phones.
We spend much of the morning inside a home, office or school.
Then, later in the evening, we surround ourselves with bright artificial light and screens.
Our brains evolved with a very different pattern: bright light during the day and darkness at night.
That is one reason researchers have become interested in the timing, intensity and duration of light exposure.
A systematic review of 45 studies found that brighter morning light was generally associated with shifts toward earlier sleep timing and improvements in some measures of sleep. (PubMed)
What does Andrew Huberman recommend?
Andrew Huberman has frequently discussed morning sunlight and circadian biology on the Huberman Lab podcast and website.
His basic message is remarkably simple:
Get outside and expose your eyes to natural daylight early in the day.
Huberman has described morning sunlight as one of his top everyday recommendations for supporting mental and physical health. He recommends getting outside relatively soon after waking, with outdoor light being useful even when the sky is cloudy. (Huberman Lab)
The reason is not simply that sunlight feels good.
The bright light entering your eyes provides a powerful timing signal to your brain's circadian system.
Morning light helps promote daytime alertness and helps establish the timing of your sleep-wake cycle later that night. (Huberman Lab)
In other words, the light you get in the morning can help tell your body when it is time to be awake and when it will eventually be time to sleep.
Could morning sunlight help you sleep better?
This is where things get particularly interesting.
It might seem strange that something you do in the morning could influence what happens at bedtime.
But your circadian system works on timing.
Bright light in the morning helps shift and anchor the body's biological clock toward the beginning of the day. Research examining light exposure has found that the timing of light matters, with brighter morning exposure generally associated with an earlier sleep period, while brighter evening exposure can push sleep timing later. (PubMed Central (PMC))
So your morning routine may be part of your nighttime routine.
Instead of thinking:
Morning sunlight = wake up
Think:
Morning sunlight = help set the clock for the entire day.
What about cloudy Canadian mornings?
Good news for those of us living in Canada.
You do not need a perfectly sunny morning for outdoor daylight to be useful.
Clouds reduce the intensity of light, but being outdoors can still provide considerably more light than typical indoor environments. Huberman specifically emphasizes that cloudy and overcast conditions still provide a useful light signal, although you may need to spend more time outdoors. (Huberman Lab)
So do not look outside on a grey Hamilton morning and think, "Well, that does not count."
It counts.
Grab your coffee, put on a jacket and step outside.
How long should you spend outside?
There is no single magic number that works for everyone because outdoor light intensity varies enormously depending on the season, weather, latitude and time of day.
Huberman has suggested approximately 5 to 10 minutes on a bright, sunny morning, with longer exposure needed when conditions are cloudy or overcast. (Huberman Lab)
The important point is not to obsess over the stopwatch.
The goal is to make morning outdoor light a consistent habit.
You could:
Take the dog for a walk
Drink your morning coffee outside
Walk around the block
Sit on the porch
Walk the kids to school
Eat breakfast near an outdoor window or patio
Take a few minutes to simply enjoy the morning
The best routine is the one you will actually do.
And no, you should not stare directly at the sun
This is an important distinction.
When people hear "get sunlight in your eyes," they sometimes interpret that as "look directly at the sun."
Do not stare directly at the sun.
The goal is to be outdoors in natural daylight and allow normal ambient light to reach your eyes. You should never look directly at the sun because intense sunlight can damage the eyes.
You also do not need to force yourself to go without sunglasses in situations where eye protection is appropriate. If you have an eye condition or have been advised by your eye-care professional to use specific protection, follow that advice.
A small habit with a bigger-picture benefit
Morning sunlight is not a miracle cure, and it should not replace good sleep habits, regular physical activity, a balanced diet or appropriate medical care.
But it is an incredibly simple habit.
Your eyes are constantly communicating with your brain about the world around you. Light is one of the most important pieces of that information.
And after a night of darkness, the morning is a particularly important time for your body to receive a clear signal that the day has begun.
So tomorrow morning, before getting lost in emails, social media or the news, try something different.
Open the door.
Step outside.
Look around.
Let your eyes experience the morning.
Your body has an internal clock. Sometimes, all it needs is a little help remembering what time it is.
A note from Viewpoint Vision Care
At Viewpoint Vision Care, we believe healthy vision is about more than simply seeing clearly. Regular eye examinations allow your eye-care team to assess your vision and monitor the health of your eyes over time.
If you have questions about your eye health, changes in your vision or how your eyes respond to light, speak with your optometrist or eye-care professional.
References:
Huberman Lab, "Using Light for Health." (Huberman Lab)
Dautovich et al., systematic review of light exposure, timing and sleep outcomes. (PubMed)
Lucas et al., review of melanopsin and intrinsically photosensitive retinal ganglion cells. (PubMed)
Huberman Lab discussions on morning light and circadian rhythms. (Huberman Lab)