A circadian rhythm is basically a process that helps to set hormonal balances within the body. It has to do with sunlight, nighttime, and overall sleep-time. The sun is actually the means by which the circadian rhythms get set for humans and children, especially.
However, we can artificially alter this circadian rhythm with the blue light that is in a computer, iPhone, or a tablet. The blue light is so strong that it will actually alter the circadian rhythm so that melatonin (a hormone that helps you fall asleep) will actually stop being produced. This is the reason to stop that screen time 2 hours before bed.
But let’s take your typical school-aged child, someone between the ages of six and ten. Sleep duration for them is going to need to be somewhere around 10 hours. That’s what you are going to shoot for. Now keep in mind, some children require more sleep. But that being said, we want sleep to occur over night. We don’t want to incorporate naps. Naps throw off the circadian rhythm, and they throw off our sleep cycle. We really want to work on increasing the sleep over night as opposed to adding a nap here or there.
That blue light in your computer and tablet is strong enough to actually stop melatonin production for up to four hours with simply a glimpse at it at bedtime. As a parent of a child with ADHD, with this knowledge about the blue light and the screen, it’s really your responsibility to help discipline your child. You need to inform them about the blue light, and explain to them, this is why after dinner none of us are going to be on any screens. This is why after dinner we are going to start the pre-sleep routine. We are going to spend time together, maybe play games, or play cards, or do something fun like that.
But we are avoiding the screen because we all need our melatonin so we get plenty of rest at night.