Blue light is an essential component of the visible light spectrum, but it is often a source of concern when it comes to our visual health and general well-being. It comes from two main sources: natural and artificial.
What is blue light?
Blue light is part of the visible light spectrum, with a wavelength between 380 and 500 nanometers. It is the most energetic of the visible lights, which means that it has a higher energy power per photon than the other colours of visible light.
Natural blue light:
Source and characteristics
The main source of natural blue light is the sun. It is present in daylight and forms an essential part of the natural lighting to which we are exposed on a daily basis.
Benefits and effects
- Circadian rhythm regulation: Natural blue light plays a crucial role in regulating our internal biological clock, or circadian rhythm. It helps maintain our sleep-wake cycle by influencing the production of melatonin, a hormone that promotes sleep.
- Mood and alertness: Appropriate exposure to natural blue light can improve mood and increase levels of alertness and cognitive performance.
- Eye health: In moderate quantities, natural blue light is beneficial to eye health, contributing to colour vision formation and visual clarity.
Artificial blue light:
Source and characteristics
Artificial blue light is emitted by a variety of sources, including computer screens, cell phones, tablets, LED TVs, as well as some indoor lighting such as LED and fluorescent bulbs.
Potential problems and effects
- Digital eye strain: Prolonged exposure to artificial blue light, particularly when using digital devices, can lead to digital eye strain, characterized by symptoms such as dry eyes, blurred vision and headaches.
- Sleep disorders: Exposure to artificial blue light, especially before bedtime, can disrupt melatonin production, delaying sleep and disrupting sleep quality.
- Risk of macular degeneration: Although research is still ongoing, some studies suggest that long-term exposure to artificial blue light may increase the risk of age-related macular degeneration (AMD), a serious eye disease.
How can I protect myself?
To minimize the negative effects of artificial blue light, here are a few practical tips:
- Use blue light filters: Many digital devices and screens offer blue light filters or night modes that reduce blue light emission.
- Follow the 20-20-20 rule: Every 20 minutes, look at an object 20 feet away (about 6 meters) for at least 20 seconds to reduce digital eye strain.
- Limit screen use before bedtime: Try to reduce screen time by at least an hour before going to sleep to avoid disrupting your circadian rhythm.
Blue light, whether natural or artificial, has significant effects on our health and well-being. While natural blue light is beneficial for our circadian rhythm and mood, artificial blue light can lead to eye strain and sleep disturbance if not managed properly. By taking steps to limit exposure to artificial blue light, such as using filters and following prevention practices, we can protect our eyes and improve our quality of life.
