How to Use Light Exposure as a Tool to Prevent Insomnia and Sleep Better at Night
The Importance of Sunlight For Our Internal Clock
Studies indicate that getting sufficient exposure to sunlight on a regular basis is very important for the stability of our internal clock. Sunlight is the crucial factor required to trigger the release of the wakefulness signal in the morning, the hormone cortisol. Subsequently, the release of cortisol sets a timer in your body. 12 to 14 hours later this will trigger the release of the sleepiness signal in the evening, the hormone melatonin.
When we wake up and open our eyes in a dark room, there isn’t enough light to trigger the correct timing of these cortisol and melatonin rhythms. It is therefore recommended to be exposed to (sun)light as early as possible after waking up. About half of the people who think they are night owls (wolfs) are actually not getting enough sunlight in the morning.
The Optimal Timing and Method of Sunlight Exposure
The neurons in our eyes that set the circadian clock respond best to sunlight. Especially morning sunlight is the most effective, when the sun is low in the sky. This is because early day sunlight contains a specific contrast of yellow and blue light. This specific contrast of light triggers the activation of the key neurons in our eyes optimally.
It is important to go outside to get direct sun exposure in the morning. This is because it is 50 times less effective to view this sunlight through a window compared to when being outside. It is essential to get this direct sunlight exposure before 9-10am when the sun is still low in the sky. If you wake up at 11am, the sun is overhead, and you are now in the circadian dead zone. Going outside at that time will not have any effect on your circadian rhythm.
How Long Should You Go Outside to Get a Sufficient Amount of Light Exposure?
Generally, it is recommended to go outside in the morning and get direct light exposure between 2 and 10 minutes. In reality, the amount of time you should spend outside to get the full benefits of light exposure depends on multiple factors. These factors include your geographical location, the current weather conditions and how bright it is outside.
You don’t need to actually see the sun directly in order to jumpstart the hormonal mechanism. Even when it is cloudy outside there is plenty of lux available in the atmosphere. However, it will take longer to obtain the required amount. It is recommended to get exposure to at least 100.000 lux before 9 am-10am. You can use a Light Meter App to determine the amount of lux in your environment.
Practical Examples How Different Factors Can Impact the Duration of Light Exposure Needed
Here is a clear example how the amount of time you need to spend outside to get the full benefits of light exposure can vary.
- Situation A: You live in Colorado, it’s the middle of winter and there is a clear blue sky.
In this situation there is going to be tremendous amounts of photon light energy arriving on your retina when walking outside. It probably will only take thirty to sixty seconds to trigger the central clock and set your cortisol and melatonin rhythms properly.
- Situation B: You live in Scandinavia, it’s the middle of winter and it is cloudy.
In this situation you may find it very difficult to be exposed to the recommended amount of 100.000 lux. This is because in this geographical location the sun shines only a couple of hours each day. In this case you can do two things. Either, you will need to stay outside for much longer in order to obtain the required sunlight exposure. Another option is to use sunlight simulating lights and related artificial light tools rich in blue light. More information on these types of artificial light tools can be found below and on the Sleep Tech page.
Other Factors That Can Help to Establish a Stable Circadian Rhythm
There are other factors that help to establish a stable circadian rhythm. These include the timing of food intake and exercise. However, light exposure is the primary and most effective way to set your natural internal clock. If you exercise first thing in the morning your body will start to build an anticipatory circuit. This will trick your body to want to wake up at that particular time you exercised during the previous 3-4 days. If you combine exercise with light exposure, you will create an even bigger wake up signal to the brain and body.
Artificial Light Tools as an Alternative For Sunlight Exposure
Some people live in a geographical location where there is not much sunlight in the morning. Or they don’t have the time to go outside every morning to get exposed to the required amount of lux. For these people there exist numerous beneficial artificial light tools. More information on these type of artificial light tools can be found on the Sleep Tech page.
However, it is important to take in mind that direct sunlight exposure is much more effective compared to artificial light. Furthermore, sunlight exposure has additional benefits as it is the most important natural source of vitamin D. Whatever you do, do not stare directly at the sun or very bright light for an extended period of time. This can cause significant damage to your retina.
The Importance of Sunlight Exposure For Our Mental Health
Studies indicate that light is a powerful signal for modulating sleep and wakefulness. Additionally, it has an important role for triggering the production of the hormones dopamine and serotonin in the body. These hormones are important for our mental health as they make us feel happy. In winter, generally the days are much shorter, so our cells get less exposure to sunlight. This is why many people suffer from depression in winter.
There are many other negative health consequences related to a lack of regular sunlight exposure. These include reduced hormonal activity, fertility and metabolism as well as elevated levels of anxiety and blood pressure. For some people these negative consequences can be severe as they are closely tied to the seasoning. These people often suffer from clinical depression in winter. If this sounds familiar to you, it is highly recommended to use some sort of light therapy to reduce the symptoms of reduced light exposure in winter. More information on these type of artificial light tools can be found on the Sleep Tech page.
How Artificial Light Tools Can be Used to Reduce the Symptoms of Insomnia
Artificial light tools can be very beneficial to people who are suffering from insomnia and/or feel tired during the day. Additionally, they can be used effectively to shift our circadian rhythm earlier. There are high tech specialized bright overhead lights on the market. These allow you to customize the timing of when you want them to turn on.
Studies indicate that setting a timer for bright overhead lights in your bedroom to turn on about an hour before your wake up will shift your circadian rhythm earlier. As a result, this will make you fall asleep faster at night and wake up earlier in the following days. More information on related artificial light tools readily available on the commercial market can be found on the Sleep Tech page.
Why You Absolutely Need to Avoid Bright (Blue) Light Exposure Late At Night
Artificial evening and nighttime light is a big cause of insomnia for many people around the world. This is described in detail on the page focused on The External Causes of Insomnia. The longer you have been awake, the more sensitive your retina is to light. Even a small amount of light in the evening from a screen or an overhead light will disrupt your sleep pattern. This will delay the release of melatonin and make it more difficult to fall asleep.
Blue LED light is especially harmful for our sleep health. This is because the light receptors in our eyes are much more sensitive to short-wavelength light within the blue spectrum. You absolutely want to stay away from bright lights after 8 pm. Especially being exposed to direct blue light late at night should be avoided at all cost. If you can’t help it or you are required for your job to stare at electronic screens in the evening, make sure you wear blue light blocking glasses.
These specialized glasses will protect your eyes from the harmful effects of electronic devices and will help to prevent insomnia caused by late night blue light exposure. Check out our full guide on the best blue light blocking glasses available on Amazon.
The Benefits of Additional Sunlight Exposure Around Sunset
In order to further stabilize and anchor your circadian rhythm it is recommended to view sunlight later in the day just before the sunset. Getting direct sunlight exposure within one hour of the sunset will signal your circadian clock that it is the end of the day. Additionally, studies indicate this will lower the retinal sensitivity. This will create a buffer which will reduce the negative impacts of blue light on melatonin release later at night.
It is recommended to go outside before the sunset without sunglasses to get direct sunlight exposure between 2 and 10 minutes. Wearing sunglasses would take 1000 times longer. Additionally, exposing your eyes to sunlight through a window would take 50 times longer to get the same effect.
Why Changing the Lights in the Evening to Red Can Make a Big Difference
Blue light exposure at night significantly disrupts your sleep pattern by delaying the release of melatonin. Additionally, studies show that bright light exposure between 11pm and 4am suppresses the release of dopamine. This causes increased feelings of unhappiness, anxiety and can lead to depression. Interestingly, red light does not cause these negative effects. So it would be a good idea to adjust the color of your lights in the evening to red.
Nowadays there are new types of lighting on the market which allow you to adjust the coloring and intensity of the lights. On the Sleep Tech and Bedroom pages, you can find different suggestions of high-tech adjustable lighting. Another option is to use candlelight or a fireplace as these don’t disrupt your internal clock. However, they pose a fire hazard which you need to take into account.
Other Ways How to Reduce the Disruptive Effect of Light Exposure At Night
There are a couple of other things you can do or take in mind to avoid the disruptive effect of light exposure at night. Studies show that your retina is more sensitive to bright light which is located high in your field of vision. Therefore, it is recommended in the evening to use dimmed lights which are low in your environment as opposed to overhead.
Generally, you should avoid watching television or working on your computer late in the evening. If you do, it is highly recommended to use blue light blocking glasses and to dim your screens. Additionally, it is recommended to install specific blue light filtering software on your electronic devices. These allow you to adjust any display’s color temperature to reduce eye strain during night-time use. These applications are free and can help reduce the negative effects of bright blue light at night. Prominent examples are f.lux and Twilight.
Blue light blocking glasses are a must have for anybody who regularly is exposed to blue light in the evening. This is because blue light blockers can help tremendously to avoid insomnia at night caused by harmful blue light exposure. Choosing the right pair of glasses can be overwhelming as there are so many options available on the market. But don’t worry, we’ve made your life easier. Check out our full guide on the 7 Best Blue Light Blocking Glasses to Prevent Insomnia and Sleep Better At Night.
An Overview of the Importance of Light Exposure to Prevent Insomnia At Night
The hormonal systems in our body are what makes us awake or sleepy at certain periods of the day. They operate by averaging when you view the brightest light. Getting regular sunlight exposure is key for establishing a consistent sleep wake rhythm and for allowing us to fall asleep easily at night. It is the foundation of proper circadian sleep health and is probably the most effective method to resolve insomnia problems.
The objective is to provide consistent powerful light anchors to your internal clock, so it is timed regularly. This is done through sunlight exposure early in the day and at sunset and by avoiding light exposure at night. This will stabilize your sleep pattern and will allow regular good sleep. Furthermore, this will create powerful benefits in all aspects of your life. These include hormonal balances, metabolism, productivity, focus, mental wellbeing, happiness etc.
