What damage does blue light cause in children in particular?
Because children's eyes are still developing, blue light can reach the retina much more efficiently and directly (i.e. more aggressively).
Dr Kokkinakis, a researcher in this field, fears that, unfortunately, it will be years before we recognise the serious problem that the use of mobile phones and similar devices poses for children's eyes.
Tablets and smartphones are already being handed to two- and three-year-olds without parents knowing enough about the serious consequences this can have for their children's health.
Parents want a little breathing space for themselves and keep their children occupied when eating out, shopping or at the doctor's by handing them small, handy "all-rounders" such as tablets and smartphones.
While blue wavelengths are hugely beneficial in daylight because they stimulate our attention, responsiveness and mood, the artificial blue light of digital devices in the evening or at night has an equally disastrous effect, because it disrupts the circadian rhythm (sleep-wake cycle) mentioned above.
The closer we hold our devices to our eyes and the more intently we stare at the screens, the less we blink, the more intense the exposure and the higher the risk of damage to the eyes.
This happens because we open our eyes much wider than when reading a book, for example.
This leads to strained, aching, dry eyes and, as a result, headaches.
This also affects many young people: in the evening, when things finally quieten down, they reach for their tablet or smartphone in bed to text friends or send selfies.
The tiredness that has just sent them to bed disappears while they read, swipe and type.
The blue wavelengths of the light emitted by tablets, smartphones and laptops make us feel alert.
We don't even notice the blue tint; the screen light is perceived as whitish.
This light acts like caffeine. The sleep hormone melatonin, the "hand" of every person's internal clock, is released by the pineal gland in the brain in the dark. Brightness, however, prevents this.
Blue light immediately signals: stay awake!
Television is considered less problematic because of the viewing distance.
To protect children's eye health, the following should be considered:
- Use a blue light screen protector on smartphones and tablets
- Let children play outdoors a lot to benefit from positive blue daylight and train their distance vision; staring at screens is causing more and more cases of short-sightedness (myopia)
- Limit screen time (max. 1 hour/day)
- Teach children about blinking and taking screen breaks
- Annual eye examinations until the age of 18
- Follow the 20-20-20 rule (get up every 20 minutes, look into the distance for 20 seconds and blink 20 times)
