Police took to social media to warn people not to get behind the wheel if their eyesight is impaired.
Prime Minister's key aide says he travelled to Durham because he was worried about his wife and child's safety in London.
The Prime Minister said his adviser had acted 'responsibly and legally and with integrity' despite claims of lockdown breaches.
The First Minister said the 'integrity' of public health advice is more important than losing an adviser.
Dominic Cummings reportedly went on a day trip during lockdown and drove up to County Durham a second time.
Boris Johnson had come under pressure to sack his top aide, Dominic Cummings.
In the letter Ian Blackford also continues his calls for Dominic Cummings to resign.