The impact of blue light on our health is both essential and harmful, depending on the time of day we are exposed to it. So, when should we embrace the benefits of blue light, and when should we steer clear of it?
Navigating what the right kind of light is and when to be exposed to it can be challenging. It becomes even more complex to grasp when we consider that getting natural daylight is beneficial for our health, yet we spend the majority of our days and lives indoors. Most people spend over 90% of their time indoors - meaning that most of us rarely get enough blue or blue-enriched light during the day, while we are bombarded with it in the evening. But why is blue light beneficial for us during the day? And why should we avoid it in the evening and at night?
Blue Light During Daytime Regulate Our Sleep at Night
Intense blue light during the day is crucial for us as it helps regulate our circadian rhythm and oversee all our bodily processes. Naturally, it is during the day when the sun's light is at its strongest, emitting the most blue-enriched light. This blue light not only energizes us and uplifts our mood but also acts as a natural antidote to depression. These practical qualities of blue light keep us alert and focused throughout the day, aligning perfectly with the abundance of natural light available for activity.
Interestingly, exposure to blue light during the day also plays a role in making us tired in the evening. This is because our body and brain absorb the blue light during daylight hours, and the more we absorb, the stronger our urge to sleep in the evening at the regular bedtime. Therefore, blue light during the day is essential for our circadian rhythm, health, and well-being. By being exposed to blue light during the day, we not only ensure that we stay healthy, alert, and active, but we also pave the way for tiredness to kick in towards the evening at the usual bedtime. Daytime light is, therefore, crucial in maintaining a stable circadian rhythm – which in turn reduces the risk of a wide range of physical and mental illnesses.
Blue Light at Night Disrupts Our Sleep
While intense white light with blue undertones is crucial during the day, it can be downright harmful for us to be exposed to it at night. This is because bright blue light at night disrupts our sleep by interfering with the body's production of melatonin. Melatonin is a hormone that signals our organs that it is dark and time for reduced activity. When our body is prevented from producing melatonin, we stay awake, thus compromising the quality of our sleep. The blue light has an invigorating effect on our bodies, much like a cup of coffee.
Stimulation by blue light is unhealthy at night because it can lead to insomnia and a disrupted circadian rhythm, ultimately resulting in serious health consequences. During the day, it is good to get blue light, as that is when we should ideally be active – but at night, it is dangerous for us because we must rest and sleep to maintain our health. By disrupting our circadian rhythm through exposure to blue light at night, we also increase the risk of a wide range of physical illnesses and health problems such as cancer, diabetes, and cardiovascular diseases, as well as mental illnesses like depression and anxiety. Naturally, it is also darkest at night, which our bodies and minds have evolutionarily adapted to and therefore crave.