The Highway Code applies to England, Scotland and Wales and is essential reading for everyone.
Vision. You MUST be able to read a vehicle number plate, in good daylight, from a distance of 20 metres (or 20.5 metres where the old style number plate is used).
If you need to wear glasses (or contact lenses) to do this, youMUST wear them at all times while driving.
The police have the power to require a driver to undertake an eyesight test.