Your eyes allow you to see the world around you. In fact, the main “job” of your eyes is to detect patterns of various lights. However, your vision depends on your brain just as much as on your eyes. This means, that your eyes need to work closely with your brain to turn those patterns into the images you see or recognise.
The downside? If you are focusing on electronic devices for a long period of time, the harmful blue light that enters your brain via your eyes can cause eyestrain, headaches, and can impair your ability to fall, and sometimes stay asleep.
In the case of our little ones, this can make it hard for them to focus or concentrate, and it can also make them tired whilst effecting their mood.
To find out more about the anatomy of the eye, check out this excellent animation from the National Eye Institute.