What is blue light?
Blue light is a part of the light spectrum with wavelengths between 380 and 500 nanometers. It is emitted by the sun, but also by artificial light sources, such as LED bulbs and screens. But only a small part of blue light is potentially dangerous: the blue-violet wavelengths. Indeed, the energy that reaches the retina in the case of blue-violet light is stronger than in the case of turquoise light, for example. However, screens diffuse peaks of blue light called high energy visible light (HEV), thus constituting a source of problematic overexposure to this type of light. This is not without consequences on the ocular structures of users, especially the youngest, whose crystalline lens does not filter these wavelengths as well.
What are the consequences of blue light on the eyes?
Scientific research has concluded that prolonged exposure to blue light radiation or artificial HEV light causes photochemical damage to the retina and lens. This is the case for age-related macular degeneration (AMD), an eye disease for which the negative effect of blue-violet light has been demonstrated. Its involvement in the development of cataracts is also suspected. Nevertheless, it is important to specify that certain wavelengths of blue light - particularly turquoise blue light - can also have beneficial effects, especially on the balance of the biological clock and on mood.
How to protect yourself from blue light?
Currently, there is no real protection against the harmful effects of blue light, even though many avenues of research are being explored. Anti-blue light filters can however be applied to screens. But they are still under-used, despite the growing awareness of health authorities regarding this issue. Several brands also offer selective photoprotection lenses. Using a specific filtering treatment, these glasses protect the eyes from wavelengths considered phototoxic for the retina. More specifically, these glasses filter blue-violet light, but allow turquoise light to pass through, in order to preserve the beneficial effects of the latter on vision and on the regulation of the internal biological clock. If the first in vitro studies suggest a real effectiveness of this type of glasses, it must now be verified and quantified in humans.
