Their is a world wide epidemic of myopia especially in Asia due to proliferation of near work: computers, iPhones, video-games, iPads and of course reading. For children the risk of developing myopia is lessened by more than an hour of outdoor activities per day. You can do internet search on this. While there is much research going on into how to prevent or temper-slow myopia nothing certain exists at present.
Go ahead and have your family and have the child spend a lot of time outdoors playing.