If someone is 86 years old and partially blind should they still drive?

If someone is 86 years old and partially blind should they still drive?
In the UK a person who has had a stroke is legally forbidden to drive for a set period after the stroke (usually one month) and after that is only allowed to resume driving if their doctor declares them fit to drive.
honestly, if they are even part blind they shouldn't drive.
I would hope this person would not want to put other drivers and children at risk by attempting to operate a motor vehicle. Hard enough to drive with good eyesight, let alone driving partially blind.