The development of digital devices has profoundly changed our daily habits. Not a day goes by without our facing a screen and, as a result, not a day without our being exposed to artificial blue light.
In the face of this growing exposure, blue-light-blocking filters and lenses are presented by opticians and other professionals in the sector as THE solution for protecting our eyes by limiting the harmful effects observed, such as eye strain, dry eyes, headaches, … but without the arguments put forward being truly demonstrated.
Because children’s eyes are immature, they let far more blue light rays (natural or artificial) through than adults’ eyes, whose lens yellows with ageing, which stops these rays from passing.
It is therefore quite natural to worry about the harmful effects of this increased exposure to blue light on children’s eyes and the potential risks to their vision. To prevent these dangers, nothing seems more logical than turning to blue-light-blocking lenses or screen filters. But to date, no study has concretely shown that blue-light-blocking lenses and filters are as effective as the sales pitch would have us believe. It even seems that wearing glasses with this type of lens has negative consequences for the brain by cutting it off from the essential supply of natural blue light emitted by the sun. Indeed, these lenses partly filter blue rays without distinguishing the source, natural or artificial, and in effect reduce the time of exposure to natural blue light. This amounts to depriving the brain of a source essential to its proper functioning, which is not without consequence for a child’s development. Indeed, the brain needs this light source to synthesise vitamins, to secrete hormones, and to regulate the alternation of our waking and sleeping time as well as the quality of the latter.
Natural light is also thought to play a part in the maturation of the eye, slowing the early development of short-sightedness. Our physiology is therefore dependent on exposure to the whole spectrum of light, starting with blue light.
So, to date, the best way to protect children’s eyes from harmful effects without depriving them of the benefits of blue light is to follow simple rules for the good use of screens. These few rules are beneficial for everyone, whatever their age, but the earlier they are learned and put into practice, the more they will become lasting habits.
For every side effect, a solution…
TIME SPENT IN FRONT OF A SCREEN
As a parent, I set an example by limiting my own screen time as much as possible.
- Screen exposure time is adapted to the child’s age.
EYE STRAIN
I take regular visual breaks : every 20 minutes I look at an object in the distance for 20 seconds.
- For a child, we pick the furthest focal point and ask them to find it with their eyes, giving them a few clues. A fun little shared moment that works their distance vision while taking their gaze off the screen.
DRY EYES
I moisten my eyes with artificial tears or saline solution.
- The butterfly eyes game : we play with the child at blinking as if the eyelids were the wings of a butterfly taking off. Blinking stimulates the natural secretion of the tear film (natural hydration).
HEADACHES
I switch on the light in the room I’m in to limit the gap between the light of my screen and that around me.
- We explain to the child that playing or reading on their digital screen in the dark is bad for their eyes and we set the rule : in the dark I sleep, I am not on a screen !
TIREDNESS
I switch off my digital screens 1 hour before sleeping and try to go to bed at a regular time. We invest in an alarm clock… A phone is not an alarm clock. Beware of electromagnetic waves.
- No screens 1 hour before bedtime, which should be at the same time every evening. No screens in the bedroom.
VITAMIN D
I look after my health by exposing myself daily to the natural light that is essential to my metabolism.
- Regular outings to parks for the youngest, outdoor sports and all open-air activities for the older ones are to be encouraged, without a mobile screen in hand. Getting some sun, even hidden behind clouds, is essential. Playing outside offers many benefits, including good regulation of the circadian cycle, a visual break away from screens, rest for visual attention from the sources of dry eyes, and it lets children anchor themselves in the real world.
Magalie MAISONNAVE-MARQUES
