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Screens:blue light, a danger to eyesight?

Screens:blue light, a danger to eyesight?

Computers, tablets or smartphones:our daily lives are now going digital. In the office or at home, in the tertiary sector as in industry, screens are an integral part of our work. Only, working on screen for several hours of the day, and this, repeatedly, exposes us to blue light, which is not without danger to health and sight.

Using too many screens is not without consequences

You have probably realized this after spending several hours working in front of your computer or watching a movie on your television, exposing your eyes to screens can cause various more or less recurring problems. Thus, it is possible to experiment:

  • Dry eye
  • Tingling;
  • Headaches;
  • Tiredness and difficulty concentrating.

This is mainly due to blue light, emitted by our screens.

Light from screens:what is it?

Blue light is a certain wavelength of visible light. It is emitted by our backlit screens:billboards, smartphones, gaming tablets, etc. These are short waves, which correspond to cold colors (blue and purple), and which are aggressive for the eyes.

Blue light is also produced by the sun. It is what allows our body to differentiate the different times of the day (sunrise, dusk, etc.), but above all to keep us awake when it is perceived. We live according to the phases of the sun and its luminosity.

How does blue light affect the body?

Blue light has an influence on balance and the internal clock. In the event of recurrent and prolonged exposure to this type of light, some people may experience sleep disorders (difficulty falling asleep or restless sleep). Indeed, the cold and bluish tint of the screens is quite aggressive for the eye. Moreover, it corresponds to that of sunrise. It therefore misleads our body into thinking it's morning, keeping it artificially active and awake. Blue light therefore disrupts our sleep rhythm by acting on melatonin. The latter is the hormone that we secrete during the night, which regulates our biological rhythm. The result:hard to come by, lower quality sleep that impairs concentration and memory.

No screen before bed!

It is also recommended not to use screens just before falling asleep. An hour before going to bed, try turning off the TV, computer, video games and smartphone:prefer to read a book, for example. Having trouble falling asleep? For example, you can meditate or listen to music, all in a calm atmosphere and dim lighting. This will allow you to rest your eyes and your mind in order to be in the best conditions for sleeping.

That's not all:blue light is also toxic to the photoreceptors of the retina, which it would damage over time. Too much exposure to it accelerates the process of degeneration of the eyeball irreversibly, by destroying certain cells. In fact, the involvement of blue light in the evolution of AMD (age-related macular degeneration), retinal disease and the development of cataracts is suspected.

How to filter blue light?

Glasses with blue light filter

Do you work on a computer? Be aware that there are glasses with a blue light filter, available from opticians. These are neutral glasses, without correction, which protect the eyes from blue light. How ? By reflecting part of the blue and violet waves before they enter the eye. Ideally, they are worn whenever you are in front of a screen:in front of a movie, in class, at work, etc. Good to know:this type of device can also be installed on corrective lenses. All you have to do is ask for this filter when you have your glasses made by an optician. Need to get prescription glasses? Discover our different health formulas for the coverage of optical care by your mutual Well-Being.

Filters on computer screens

Another possibility is to reduce the coloration of the light emitted by your screen directly on it. In particular, there are free applications to install on your computer, which allow you to modulate the brightness and color of the screen. f.lux, a free application for computers, installs a warm color filter on your screen, which can be programmed according to the sunset in order to adapt to natural light. Some operating systems also offer an anti-blue light option, such as Windows 10 in the "Display" section of "System Settings". Same thing on Mac, with the "Night Shift" mode, available in the "Monitors" tab of the settings.

… And a smartphone!

On a smartphone, we can cite the Twilight mobile application, or even Cf.Lumen. In the same way as on computers, blue light can also be filtered directly in the settings of an iPhone, without going through an application. This option is available on some Android phones under the "Eye comfort" setting in the screen control panel. In addition to the warm color, also remember to adjust the brightness of your screens, which does not need to be strong and aggressive when you are indoors. Be careful though:these filter devices, whether on the screen or on glasses, do not fully retain blue light. Indeed, if necessary, the colors would be too altered. The intensity of the various blue tints is reduced, but the blue light is not entirely suppressed. In the case of glasses, we speak of a filtration equal to 30 or 40%.

Protecting your eyes from the blue light of screens is important to avoid exposing them to harmful and irreversible consequences. Whether installed on the computer and the smartphone, or integrated into glasses, a blue light filter can in particular help to avoid eye fatigue and its repercussions on sleep.