Focus Games for Kids
Active Focus is a difficult concept to convey, even more so to children. For this reason we largely stick to encouraging children to engage with their vision in the most natural way possible; through play. Keep in mind that tracking motion is a great means to engage with vision, and shifting focus is highly important as well. What is most important is that you find things your child will want to do, if their vision improvement journey becomes a chore they are less likely to participate.
You know your child best, consider their interests and be creative. Just being away from that static close up distance is a great start, so things like swimming, fishing, hiking and playing on the playground are good. The more your child is engaged with their vision the better. Engaging with distance vision is what improves distance vision.
Activities to engage vision
Bird spotting, animal watching, kite flying, remote controls, I-spy, counting games (leaves, flower pedals, how many of a predetermined number or letter they can spot on a walk or drive through town etc), star gazing,light bug spotting, finding shapes in the clouds, and all kinds of sports.
Literally every sport engages vision at various distances and requires some motion tracking and detail in vision, but if you are having trouble getting the proverbial ball rolling here is a short list: soccer, football, badminton, frisbee, tag, catch, baseball, basketball, biking, bowling, golf, archery, darts and all sorts of target type games, tennis, ping pong, ring toss, bean bag toss and other similar games and naturally the list could go on for quite sometime.
Engaging your child in their stimulus
Have a craft time and create visual aids with your child. Pick something your child likes and make 6 to 10 of them with one or two small detail variables and turn them into magnets. For example butterflies with varying numbers of spots, flowers with different numbers of pedals, monsters with different numbers of eyes or arms, wheels with different numbers of spokes, their favorite character with different expressions, make it personal to your child. Now you have an engaging set of visual aids that you can rearrange on the fridge. This could make for a great way to spot test vision without adding the anxiety of measuring officially.
If you are feeling particularly brave you could play a blindfold game. You could take turns with your child, though them being the eyes is the point. You would submit to being blindfolded and get your child to describe in detail everything they see. You can ask questions to encourage them to be more attentive to details. If you are not feeling brave enough for the blindfold and you are myopic, wear your lower correction (or none) and have them 'help' you active focus by describing the details they can see. Most kids are competitive enough to find such a game very engaging if they are working from the notion their younger, superior, eyes are giving them an advantage, besides that this will positively reinforce a desire for them to see well. You can make the details of the game line up with your child's interests. This game is also an opportunity for you to gain insight into how your child views their world.
Overall the point is not to get your child to try to force focus, just engage with their vision, if they have better vision habits and a genuine desire to see well because they are engaged with an activity, their eyes will do the rest. It is important to discourage squinting and blinking unnaturally hard in order to clear blur. These are both bad habits to form and difficult to break. The eyes will focus on their own, with incentive and opportunity. The incentive being something they want to see and the opportunity being a manageable amount of blur.