I am 72 have driven since 1960. I renew my licence as a precaution but would be perfectly happy to let my wife do the driving now. It is not a pleasure anymore and a chore most of the time.
When you reach 70 your licence expires and you apply for another. There is no test whatsover either medical or driving. I think that you should have to have a test from your doctor that you are physically and mentally alert and your eyesight is ok to drive, not just you sign a form to say...