The Dark Side of Blue Light


Our body uses the blue light (in the blue-turquoise frequency) from the sun to regulate our circadian rhythm of sleeping and waking. This natural blue light also promotes vigilance, improves reaction times, and enhances mood, engendering a sense of well-being. But did you know that the light in the blue-violet part of this spectrum can actually damage your eyes?

As you can see on the image below, light comes in different wavelengths, corresponding to different colours.

Note that the spectrum of visible light—what we can see with the naked eye—stretches from red to violet. As you move further toward the violet end of the spectrum, the waves grow shorter and the energy intensity increases, hence the potential for eye damage. Violet has a wavelength of approximately 380 nm, versus red’s much longer 780 nm. Blue is somewhere in between, around 440 nm.

Unfortunately, our eyes’ natural filters do not adequately protect us against the blue-violet light generated by the sun, let alone the blue light (also known as high energy visible [HEV] light) produced by electronic equipment such as mobile phones and computers. Prolonged exposure to this blue light can damage the retina and help cause age-related macular degeneration, which may lead to blindness. Too much screen-time can also cause eye fatigue and headaches.

Luckily, treated ophthalmic lenses that can filter out harmful blue light are available. These lenses have a coating that filters blue light, so the dangerous part of the spectrum is blocked, but not the beneficial light. To find out more about the best solution for you, consult your Opto-Réseau eye care professional.