In the summer months, our mornings get brighter and our days ever longer. Fast forward into winter, we commute to work guided by bright street lights and leave the office under the same darkness. We open our eyes and stare at our screens before we even open the curtains, and in the evenings our faces are illuminated by tablets and Netflix documentaries. We often comment on how hard it is to get to sleep when it is light outside, or how tired we feel when we wakeup before the sun does, but have you ever stopped to wonder just why this is?
If you struggle to sleep regardless of the time of night, well the answer could be buried in your exposure to light and your late night habits. Take a dive with me into the power of light and how you can use it to your advantage.
THE SCIENCE WITH LIGHT AND SLEEP
So why do we feel so tired when the sun goes down? This all relates to a nifty thing called your circadian rhythm, which is essentially your 24-hour internal clock that runs in regular cycles between when you are tired and when you are more awake and alert.
Light helps to influence your circadian rhythm, thanks to specific light sensitive cells found in our retina. These cells detect light and then send messages to the brain letting our bodies know what time of day it is and how to react accordingly with the production of hormones. As light begins to fade in the evening, our body temperature falls and the hormone melatonin begins to rise helping us to feel sleepy and less alert. As the day breaks, the amount of melatonin in our system begins to slowly decrease making us feel more awake.
Because light stimulates the production of melatonin, your body links this to your circadian rhythm, which explains why you will generally feel more tired when it is dark. In order to keep a regular rhythm, keeping consistent sleep habits and ‘good sleep hygiene’ is essential, and one of the things which can help implement this is your exposure to natural and artificial light.
IT’S ALL ABOUT THE TYPE
Artificial light has made so much in our life possible – technology to support our work from home life, entertainment for cozy nights in or even just keeping our house lit whilst we potter about in the evenings. But our exposure to this light – especially late into the evening – can have an adverse effect on our ability to drift off peacefully.
One of the most significant examples of the disruptive nature of artificial light comes in the form of blue light. Blue light is emitted from all of our favourite digital devices. Phones, tablets, e-readers, laptops and TV screens all emit a short wavelength which sends signals to your internal clock to suppress the natural production of melatonin. Whilst this blue light may be beneficial during the day to help boost your mood and concentration, it has a significant impact on our circadian rhythms if we use it too much during evening hours, making it harder to fall, and indeed stay, asleep.
With bright lights blaring at us throughout the evening until we finally lock our screens and turn out the light, our brains have no time to switch off and feel tired, not only because we are constantly connected to the world, but because the light from our tech is stimulating our brain to think that it is in fact daytime.
Beware of the science though, as recent studies conducted in the last year have called into question the once universally accepted fact that blue light is the source of all our restless nights. Read this article to get informed on the discourse surrounding blue light at its effects with a wonderful quote from Dr. Cathy Goldstein who claims; ’“blue light has become the gluten of the sleep world”’.
HOW TO GET THOSE Z’S
When it comes to artificial light, there are a number of products on the market which claim to block our exposure to blue light (such as glasses or screen covers) reducing the signal to the brain that tells it to stay awake. Many phones now have a night-shift mode which switches the blue light to a warmer, redder wavelength which has less of an impact on our circadian rhythms. Using these, particularly in the evening, will help increase your chances of getting a better nights sleep.
However, whilst these products may mitigate the impact, one of the best things you can do is reduce your exposure. Simple things like putting your phone away an hour before bed or not taking your phone or tablet into the bedroom will make a significant difference. Take some time to read a book or listen to music instead of watching TV or scrolling through Instagram, it will help your mind to wind down and trigger the hormones we need in order to feel sleepy.
Not all light has been created equal, however. Many studies have found that light can actually be used as an effective noninvasive therapeutic option which can help significantly with sleep, mood and general well-being. The key to using light to your advantage when it comes to sleep is to get as much natural light as possible. At high intensities, natural daylight has been shown to advance the timing of sleep, affect the duration, and even improve sleep quality. In fact, several studies have reported that exposure to white light is associated with an increase in evening fatigue and sleep quality.
HOW TO GET THOSE Z’S
So how can we use natural light in our favour to get the perfect night’s rest? First, daily exposure to outdoor natural light will help not only with your ability to sleep, but it will also greatly improve your mood. Try to aim for thirty minutes to an hour of time outside a day as a minimum. Try to use blinds or curtains which block out as much light as possible during the night that are easy to pull back in the morning. Exposure to sunlight as you wake helps alert your brain and reduce tiredness.
During winter months, however, access to glorious bright light becomes increasingly difficult and often we arise in the cover of darkness. This is when things such as Seasonal Affective Disorder can begin to have a real impact, and our ability to sleep or wake up can be disrupted. To help mitigate this, look into investing in lights designed for SAD, or dawn-simulating alarms such as this, which mimic natural daylight helping to keep consistency in your natural sleep rhythms.
Our differing exposure to light may not be the only reason we struggle to fall asleep or wake up in the morning – read last week’s Sleep Series piece to learn how what we drink can impact our eight hours. But by increasing our exposure to natural light and reducing our contact with artificial sources, we can start to form healthier sleeping habits which will make a world of difference to your body and your mind.