What you need to know about blue light
Introduction
Light is an integral part of our daily lives, whether it comes from the sun or the digital devices we constantly use. Among the different wavelengths that make up visible light, blue light is of particular interest because of its potentially harmful effects on the eyes. This article explains in detail what blue light is, its effects, where it is found, and how to protect yourself effectively from it.
What is blue light?
Light is divided into two categories: visible light and invisible light. UV light, for example, is invisible and comes primarily from the sun. Visible light, on the other hand, corresponds to the colors our eyes perceive: violet, indigo, blue, green, yellow, orange, and red—the seven colors of the rainbow. Blue light lies in a range from turquoise to violet. It corresponds to wavelengths between 380 and 500 nanometers. It is naturally emitted by the sun, but also by many artificial sources: screens (computers, phones, tablets, televisions), LED lighting, etc.
The potentially dangerous part of this light is blue-violet, a high energy visible (HEV) range. Screens, in particular, emit significant peaks in this range.
Is blue light harmful to the eyes?
Some in vitro studies have shown that wavelengths between 415 and 455 nm are the most toxic to retinal cells. This range corresponds precisely to blue-violet. Prolonged exposure to this artificial HEV light can cause photochemical damage to the retina and lens. It is considered a risk factor in the development of AMD (age-related macular degeneration) and cataracts.
However, blue light is not only harmful. Turquoise blue light (approximately 490 nm) plays an essential role in regulating: circadian rhythms (wakefulness/sleep) mood melatonin production This is why it is important to filter only the harmful blue light, without blocking the beneficial blue light.
Where is harmful blue light found?
Harmful blue light is everywhere:
Outdoors: The sun is the most intense source of blue light. Outdoor exposure can be 100 to 500 times stronger than that from screens. The sky appears blue precisely because of this light.
Indoors: We are exposed to blue light through:
digital screens
LED lighting
electronic devices
This constant exposure contributes to eye strain and discomfort.
The effectiveness of blue light blocking glasses
Blue light blocking lenses are designed to filter harmful wavelengths (blue-violet) while
allowing the turquoise blue light, essential for visual well-being, to pass through.
How they work:
They filter the wavelengths identified as toxic to the retina.
They preserve the light useful for biological regulation.
They often have a slight purple tint, characteristic of the filter.
Although the exact effectiveness in humans is not yet quantifiable, these lenses block a significant portion of harmful wavelengths, suggesting real protection for retinal cells.
How do Transitions lenses protect against blue light?
Transitions lenses offer protection both indoors and outdoors. Transitions Signature filter 1.4 times more harmful blue light than standard clear lenses indoors. Outdoors, they filter more than 8 times the amount filtered by clear lenses. Transitions XTRActive filter at least 2 times more harmful blue light indoors. Transitions Vantage filter twice as much harmful blue light indoors. These adaptive lenses offer continuous protection while automatically adjusting to the light.
Who should wear blue light blocking glasses?
Virtually everyone can benefit, especially if you are exposed to blue-violet light for more than 30 minutes a day—which is the case for most people. They are particularly recommended if you: work in front of a screen all day spend a lot of time outdoors have a family history of age-related macular degeneration (AMD) or cataracts
Note: not all lenses filter the same amount of blue light. It is important to choose a model suited to your needs.
For personalized advice, come and meet the team at LOPTICIEN.CA.
Conclusion
Blue light is an integral part of our environment, but certain wavelengths can be harmful to the eyes. Thanks to blue light blocking lenses and Transitions lenses, it is possible to reduce exposure to harmful wavelengths while preserving the beneficial effects of light.
To choose the protection best suited to your lifestyle, don't hesitate to consult an eye care professional.