I’ve been able to do it since I was young about 5 and I thought everyone else could probably do it but I kept to myself til I’m about to be 21 and realizing I can still control the focus of my vision without going cross eyed or getting fatigued; unless I do for a long period of time. This entry is probably late but I think more research should be made if it’s evolutionary or adaptation of muscles within the eyes that can be more easily achieved at a young age. I think the best part about having control of it though is being able to see lights enhanced more, especially at night