It would involve so much work and cost so much to make happen. Firstly your need legislation - so that’ll be quick. 😆 Then you need to actually design and develop complex, multi-provider services to ensure that the right kinds of testing are done and the results communicated where and how you want them. And these services will need to integrate with existing services. And then, once you’ve navigated your way through that… you need to operate those services.
Without significant evidence that licensing that requires people to have biannual eye tests would actually solve a significant problem (the problem itself still being very poorly defined, as people have rushed to solutions), it’ll never happen. Is there a significant problem with drivers of all ages having car accidents because they haven’t had an eye test in the last two years in the UK? Even if there is that exact problem (not a different one, like people not wearing their glasses), would the proposed solution make any difference?