Honestly, the best thing you can do is not let them use the computer at all
But that’s not really feasible in the world we live in today
So here a couple of things that you can do to save their eyes:
Reduce the PWM flicker, monitors turn on and off, thousands of times per second.
It is so fast that our eyes can’t even see it but our brains can and it’s really harmful
Take regular breaks from the computer, you can use some sort of timer to remind you so you don’t forget to take a break
You can apply the famous 20–20–20 rule here:
Reduce Blue Light, almost everything emits blue light, screens of any time are especially dangerous. This is really harmful to our eyes, sleep and overall health.
You can do all 3 things and much more with a program like Iris
It is the only program that can block the PWM flicker of any monitor and is probably the best blue light blocking application out there
You can read more about blue light here:
How Blue light Destroyed our Sleep? – Iris – Software for Eye protection, Health and Productivity
And PWM Flicker:
How Мonitors Destroyed our Eyes? – Iris – Software for Eye protection, Health and Productivity