Blue light has become a hot topic of discussion, especially with the rise of screens in our daily lives. Our phones, computers, tablets and even some light bulbs emit blue light. But what exactly is this light, and why does it attract so much attention?
What is blue light?
Blue light is part of the visible light spectrum, which includes all the colours of light we can perceive with the naked eye. It is at the high-energy end of the visible spectrum, with wavelengths between 380 and 500 nanometers.
Among these wavelengths, high-energy blue light (HEV) is particularly powerful. Unlike other types of visible light, it has sufficient energy to penetrate deep into the eye, reaching the retina directly.
Why is blue light a concern?
The problem with blue light lies not just in its presence in our environment but in the quantity we are exposed to. Historically, we were only exposed to blue light via the sun. However, digital screens are ubiquitous today, emitting a significant amount of artificial blue light.
Overexposure to this light has several consequences, including:
Digital eye strain: Our eyes get tired when we spend long hours in front of screens. Blue light is one of the factors responsible for this fatigue, as it causes glare and reduces visual contrast, making it harder to focus.
Sleep disruption: Blue light directly affects the production of melatonin, the sleep hormone. Blue light can disrupt our circadian rhythm by inhibiting melatonin, making it harder to fall asleep and reducing sleep quality. That's why we often recommend avoiding screens before bedtime.
Benefits despite everything?
It's important to note that blue light isn't all bad. As mentioned above, it is present in natural sunlight and is essential in regulating mood and alertness. Moderate exposure to blue light during the day can improve concentration, stimulate memory, and boost general well-being.
How can we protect ourselves from blue light?
Fortunately, there are several ways to protect yourself from blue light while enjoying the benefits of modern technology:
- Screen filters: Many devices now offer filters or “night” modes that reduce the amount of blue light emitted. We recommend activating these filters in the evening to minimize the impact on sleep.
- Blue-light filtering glasses: These glasses are specially designed to block or reduce the blue light emitted by screens. They can be handy for those who spend much time in front of a computer or phone.
- Limiting screen time: One of the best ways to protect your eyes is to reduce screen time. It's also advisable to take regular breaks, such as the 20-20-20 rule: every 20 minutes, look at an object 20 feet away (about 6 meters) for 20 seconds.
- Ambient lighting: Avoid overly bright light sources in the evening and opt for softer lighting. Low-emission blue light bulbs are also available.
Blue light is a natural phenomenon that we have always lived with. However, our exposure to them has increased considerably with the rise of digital screens. Science is helping us understand the potential effects of this overexposure on our health, including eye fatigue, sleep disruption, and retinal health. Fortunately, there are simple and practical solutions to protect our eyes while continuing to enjoy the benefits of technology.
Ultimately, the key is moderation, as with so many things in life.
