Our bodies follow the cycles mandated by the sunlight, when the sun goes down its light is dimmer and warmer and our body receives the message: “sleep time approaching, prepare for bed” so it starts producing Melatonin. 

Melatonin is a natural hormone that allows us to feel sleepy and to fall asleep.

Our bodies have a 24h internal clock known as the Circadian Rhythm that helps regulate every function of the body according to the daylight cycle. It is the color and intensity of the light that indicates to our bodies what we need to do next so the body can prepare for it. 

If we would spend most of the day outdoors exposed to the sunlight, we would be perfectly in sync with the natural rhythm; though we spend most of our days indoors exposed to artificial lighting so we need to understand the daylight cycle to get the best from it.

Daylight cycle. How sunlight changes during the day

From the moment the sun rises until it sets, the intensity and color of its light changes. When the sun is high in the sky the sunlight rays travel a shorter distance through the atmosphere and the resulting light is of blue color.

During sunrise or sunset, the sun is closer to the horizon and its light travels a longer distance through the atmosphere, which results in a light that contains more yellows, oranges and reds.

Image by The Lighting Practice

Our body adapts to the different light colors

One of the most important activities regulated by this cycle of light is sleep. When the light starts losing intensity and shifts towards a reddish color our bodies understand it is time to start to slow down and they start preparing for the night. 

It is then that they start producing the hormone Melatonin, the hormone that allows us to feel sleepy and fall asleep. Melatonin is very sensitive to light and specially to blue light, so as soon as we are exposed to a more intense and bluish light, the production of melatonin stops.

Schedule your light exposure at home for a better sleep

Understanding how the circadian rhythm works and the relationship between blue light and sleep is key to creating a healthy light schedule at home and avoiding insomnia.

Choose a cooler light during the day

During the day and specially at work a cooler white light will promote a higher awareness keeping you awake and productive. Try to replicate the sunlight cycle at home and use cool white lights during working hours.

At night avoid blue light and cool white lights

As soon as two hours before sleep -but more importantly half an hour before bed time- start shifting your light exposure to a dimmer and warmer one. Here is a list with some of the thinks you can easily do to schedule your light for a better sleep: 

• Reduce the exposure to computer, TV and phone screens at night.
• If you choose to watch something on your screens use a night filter that shifts the cool white light to a much warmer color. 
• Switch off the cool white lights and create a warmer environment at home with warm colored lights. 
• Choose a night light with fewer lumens (intensity) and warmer light color.
• If you are struggling with severe insomnia you can even try to wear dark sunglasses two hours before bedtime to reduce even more the exposure to light.