Older people tend to be more cautious, because they know their reactions are slower. Older people usually have more eye check ups than younger people too.
I think the driving test should be re-taken every 10 years regardless of age. Getting older doesn't mean indicators suddenly stop working.
There are full time working drivers aged over 60 considering they don't retire until 67 nowadays.
You don't suddenly lose your marbles or reactions when you reach your 60th birthday.