If memory serves, once she reached 80 (and she was still more or less okay, although she was beginning to decline), my mother had to renew her driving licence every three years (along with taking an eye test and submitting a doctor's cert/note each time) rather than every ten.
I also recall how passionate the doctor was in attempting to retain the independence of her elderly patients, pointing out that many simply gave up mentally, or psychologically, feeling - keenly - the removal of their independence - once the ability to motor or drive even locally - to the shops, for appointments, for example - had been removed from them. Actually, I remember that the GP quoted one of her patients remarking that "you might as well shoot me now" as remove her ability to drive.
In any case, my mother took the decision herself to stop driving, as she no longer felt comfortable - or safe - while driving, even locally, - she knew that she was deteriorating by then - around 18 months after that particular appointment, but a year or so before she was formally diagnosed; likewise, with my father. When he knew he was declining - and his eyesight was deteriorating - he (although completely mentally sharp) simply stopped driving, and relied on either public transport, or my mother to drive him, or, locally, on foot, to get around.