As difficult as it may be to get children to stop watching television or using their electronic devices before going to bed, there is a compelling reason to do so. The blue light emitted by these displays can delay the release of sleep-inducing melatonin, increase alertness, and reset the body’s internal clock (or circadian rhythm) to a later schedule.

This is a particularly important problem for adolescents whose circadian rhythms are already moving naturally, which makes them wake up later in the night.

The end result: children deprived of sleep or poorly rested who will be mainly affected by a mini-case of jet lag.

See also: How smartphone light affects your brain and body (infographic)

The reason blue light is so problematic is that it has a short wavelength that affects melatonin levels more than any other wavelength. The light of fluorescent bulbs and LED lights can produce the same effect. Normally, the pineal gland in the brain begins to release melatonin a few hours before bedtime, and melatonin peaks in the middle of the night.

When people read on a device that emits blue light (like a tablet, rather than a printed book) in the evening, they need more time to fall asleep; In addition, they tend to have less paradoxical sleep (when dreams come up) and wake up more tired, even after eight hours of sleep.

Consider these effects as good reasons to impose a digital curfew on your children. Ask them to turn off their electronic devices, including television, an hour or two before bedtime so that their body can start producing more melatonin. If that’s just not possible – if they have to finish their homework on a computer, for example – turn down the screen brightness. Or use blue anti-reflective glasses.

Click on the image to see the glasses:

Or, you can install an application that automatically heats the colors on the screen – away from the blue and towards the reds and yellows – at sunset. Also avoid using energy-saving bulbs (blue) in the light bulbs in bedrooms and bathrooms.

Instead, opt for dim red lights because the red light has a longer wavelength and does not suppress the release of melatonin.