It reduces the accommodative effort (the effort needed by the ciliary muscles of the eye to focus on near objects). By looking at objects far away, it tends to relax your eye muscles.
I would recommend parents teach their kids good habits to help with any eyestrain they feel. Taking regular vision breaks or going outside during near work can help the kid slow down myopia.
These breaks can be as short as 3 to 5 minutes. It can be done even by looking outside the window into the distance or nearby trees.
