Blue light is a familiar and divisive talking point in the 21st century, due to the rise of LCD screen technologies, particularly laptops, smartphones, and tablets.

This means that a large proportion of the population now have a near-constant exposure to sources of blue light. For example, according to The Independent we currently average over 6 hours per day in screen time.

Due to the relatively recent explosion in popularity of modern smart devices, there are still many unknowns about the long-term effects of blue light. As a result, painting a clear picture of the effects can be difficult. However, we will share some of the concrete truths as we investigate.

What is blue light, and where does it come from?

We roughly define blue light as light between 380nm and 500nm. It may not surprise, but most of the light we experience here on Earth comes from the sun. This means that blue light is something we are naturally exposed to, and it has an important role in our internal body clocks, or circadian rhythms.

The highest blue-light content occurs during the morning, and it is believed that this is why a response of our circadian rhythm evolved to be influenced by blue light exposure. Blue light suppresses melatonin, which is the hormone which helps us to fall asleep and will maintain our sleep throughout the night. When it is suppressed, we naturally become more alert.

However, problems start to arise when we experience blue light sources before we try to go to sleep. Our brain interprets the waves of light in the 380-500 spectrum as a sign to stop producing melatonin, which is exactly the opposite of what we want when we’re going to bed.

This is why the most common guidance regarding blue light devices is that we should not use them in the two hours before we go to bed.

Health risks associated with blue light

The most prominent health-risks associated with blue light are conditions related to a lack of sleep. This can cause stress, fatigue, and exacerbate other difficult conditions to live with, such as diabetes.

Blue light is also associated with chronic eye strain and digital eye strain, with the bright blues needed to create the colour white on an LCD screen seeming to lead to discomfort if endured for many hours.

Does blue light cause retinal damage?

There has been a lot written about how highly intense waves of blue light may lead to cell death, and while studies have demonstrated certain blue light frequencies cause cell death in mice, British schools of optometry are yet to be convinced. The line of argument here is that there is no way to experience the highly intense waves of blue light that were administered to the retinas of mice, so it is not something that will affect us every day.

Currently, the General Optical Council is in agreement that there is no evidence demonstrating increased cell death in humans in natural circumstances. This resulted in a controversial incident, where Boots Opticians were fined £40,000 for misleading advertisements back in 2017.

A Serious Solution

While the jury is still out on the retinal danger of blue light, people should certainly try to avoid the negative effects of blue light on their circadian rhythms - especially now that evenings are growing longer. The Daylight Wavelength Technology™ present in Serious Lights mitigates these harmful drawbacks by avoiding a spike in blue light. Comfort is key when it comes to relaxation and enjoyment of a good book, and there is nothing more comfortable than the knowledge that your eyes are safer, and your treasured hobbies will be protected.

Sources:

1. AOP.
2. Health Harvard.
3. RNIB.
4. Independent.