In previous posts, we discovered some of the reasons why people develop insomnia.
In cognitive behavioral therapy for insomnia (CBT-I), techniques are used that, among other purposes, manipulate your sleep pressure and biological clock to regulate and improve your sleep.
There is evidence that in addition to the classic factors that explain the development of insomnia, a possible factor that causes insomnia is a dysregulation of your biological clock with your sleep schedule.
Specifically:
- those who have difficulty falling asleep may have a delayed biological clock1
- those who wake up earlier than desired and cannot fall back asleep may have an advanced biological clock1
One way to improve sleep is to synchronize your biological clock to a schedule that suits your needs, and this can be done through exposure to bright light, a concept known as light therapy.
Light Therapy
In light therapy, people who have difficulty falling asleep can expose themselves to bright light in the morning, advancing the biological clock, making it easier for them to fall asleep faster at night and wake up earlier. Conversely, people who wake up earlier than desired should expose themselves to light in the evening.
Light therapy is not part of most CBT-I interventions. However, there are many studies that demonstrate a solid and positive benefit.
Does it work as well as stimulus control and sleep restriction? Of course not. These techniques are still the best thing you can do for insomnia. But light therapy can still be another powerful tool to improve your sleep2.
How to apply light therapy?
For people who have difficulty falling asleep:
- The light therapy session should occur within your first hour after waking up (many people like to do this while having breakfast or when they arrive at work)
- You should expose yourself to light for 20 to 30 minutes every morning.
- If you can expose yourself to morning light outdoors, that is ideal, otherwise, you can use an artificial light device (see recommendation below).
- If you are using an artificial light device, place it between 45 and 60 centimeters from your eyes. You don't need to look directly at the light, but you need to have it pointed at your face.
- It is recommended that you avoid exposure to bright light 1 to 2 hours before going to bed (see recommendations below).
For people who wake up earlier than desired:
- The light therapy session should occur in the period before going to bed (many people like to do this while watching television, reading, or doing some activity just before sleeping)
- You should expose yourself to light for 20 to 30 minutes.
- In this case, it is not possible to use natural daylight, so an artificial light device should be most appropriate (see recommendation below).
- It is recommended to avoid too much light exposure during the mornings.
Does it work for everyone?
Remember that this therapy's main objective is to synchronize your biological clock if it is dysregulated.
If your biological clock is properly synchronized, then your insomnia is related to other factors.
If you use this therapy improperly, you may end up worsening your insomnia, so we recommend that you talk to a specialist doctor about the potential risks and benefits of light therapy if you are thinking about trying it.
How to avoid light in the evening?
Ideally, your only source of light in life should be the sun. This would be ideal for your circadian cycle, but we have moved past that era and we know that currently this is not very feasible.
So, what you can do is reduce exposure to electric light 1 to 2 hours before going to sleep. You can take this time to do activities that don't require TV or phone such as:
- Relaxation exercises (e.g., deep breathing, progressive muscle relaxation, etc.)
- Cognitive techniques (e.g., thought parking, etc.)
- Preparing things for the next day (e.g., clothes, backpack, etc.)
If you really need to use your phone or computer on a given day, there are ways to reduce the impact of light exposure from these devices:
- Lowering the brightness of your devices
- Using device settings for "night mode" that reduces the amount of blue light from the screen. If you have an iPhone use these instructions, for Android we recommend downloading the Twilight app, and for your computer we recommend flux.
- Using glasses that filter blue light (you can find them on most major e-commerce sites).
Where to buy a light-emitting device for light therapy?
You should buy a device that emits white light at 10,000 lux (a device that allows a light therapy session in 30 minutes; for lower power levels, longer exposure time would be necessary).
Although it is difficult to find this device in the Brazilian market, we found that Mercado Livre offers some options. Search for the term: "Energy Therapy Lamp Light 10,000 Lux".
It is important to say that we have no relationship with any seller and we do not guarantee the quality of any equipment you may purchase.
My workplace is already very well lit, do I really need the outdoors or a device?
There is a way to measure the intensity of light perceived by our eyes. This is measured with a unit called lux.
An office typically has 80 lux, while sunlight ranges between 10,000 and 30,000 lux!
With this huge difference, it's easy to understand why it's important to expose yourself to morning light outdoors, or with a specific device.
