Morning Sunlight Can Change Your Sleep
When is the last time you got sunlight exposure immediately
upon awakening? Was it on a camping trip long ago? If you are like most people,
you have likely lost an intimate connection to our planet’s most important
influence. How does sunlight affect our timing of sleep and support
wakefulness? Learn about this natural relationship and how it might impact
unexpected aspects of our health, including
rhythm sleep disorders and even metabolism.
A Trip Back in Time
To understand how important morning light is in our lives, let’s imagine
life 40,000 years ago as a neanderthal. If you were lucky, perhaps you lived in
a cave dwelling, but it is likely you were even more exposed. When the sun set,
it was time to bed down and go to sleep. If you didn’t, there was a real
possibility that your safety and health were at risk – either due to exposure
to the elements or from predators. Spending 8 hours in a state of
unconsciousness is not the ideal way to defend yourself. You might sleep
alongside others for added protection.
When the sun came up, it would be time to rouse and resume the search (or
work) for food. With light, it was no longer safe to lie unconscious. Morning
sunlight evolved as an intense signal to the brain that promotes wakefulness.
Its profound influence on the timing of sleep and wakefulness is linked to its
influence on the body’s
Light’s Impact on the Body
All light enters the eye and via the retina travels along the optic nerve to
Each optic nerve crosses at the optic chiasm and
just above this is the hypothalamus.
The hypothalamus is like a control system for the body, influencing the
circadian (Latin for “near day”) timing of sleep and wakefulness, hormone
release, and metabolism. The
nucleus within the hypothalamus takes the information from light andtranslates it into influences on the body’s processes.
Sleep is dependent on both the sleep drive
and circadian rhythm. Although the circadian rhythm will persist without
external influence, consistent with its genetic basis, sunlight powerfully
controls it. In particular, morning sunlight can initiate the circadian
alerting signal during the day and impacts the timing of sleep at night.
Therefore, getting sunlight upon awakening can improve daytime sleepiness
and ease insomnia,
especially among night owls with
How and When to Get Morning Sunlight
In order to improve your pattern of sleep and wakefulness, it is best to get
morning sunlight exposure immediately upon awakening. Sunlight is best as it is
a broad spectrum of light and quite potent, with 100,000 lux of intensity. For
comparison, room lights may be 1,000 lux and an expensive light box
may be 10,000 lux. It is necessary to wait for sunrise, and if you live at
northern latitudes in the winter, it may be hard to get light exposure into
your morning routine. Therefore, a light box may be necessary.
Try to go outside upon awakening (of after sunrise) and get direct light
into your eyes. It is unnecessary (and unsafe) to stare directly into the sun.
Instead, avert your gaze and let the sun wash over your face. Don’t wear
sunglasses or hats with bills or visors. If concerned, apply sunscreen, though
the sun’s morning light is less intense. Spend 15 to 30 minutes in the
sunlight. It is the perfect time to go for a walk, eat breakfast, have a cup of
coffee, read the newspaper, or admire your garden.
Sunlight filtered through a layer of clouds or obtained from inside through
windows is less intense. It may still help some, and if this is your only
option, it may be good enough. Don’t let weather determine if you are going
outside. Try to go out every day to keep the habit, no matter the weather. As
needed, dress warmly or bring an umbrella. Even when filtered through clouds or
rain, the sunlight will continue to have its effect.
Our bodies respond best to a regular sleep schedule with a consistent
bedtime and wake time. You may be surprised how getting just 15 minutes of
sunlight upon awakening can help you to sleep and feel better. If you struggle
with getting to sleep or feeling alert during the day, speak with a
specialist about other ways you might improve your rest.
Health and Wellness Associates