First thing's first - before you can begin learning to drive a car, you will need
to apply for a UK provisional car licence, and this must be in your possession before
any 
driving can take place.
If you are in receipt of the higher rate of disability allowance, you can start to learn to drive from age 16, otherwise you will have to wait until you turn 17. You can, however, apply for your licence up to 3 months before your licence is due to start (although you must wait until your licence starts before you can drive on the road, or sit a Theory Test).
You will also need to satisfy the eyesight requirements for driving, namely being able to read an old style number plate (A123 BCD) from 20.5 metres away or the new style number plate (AB51 ABC) from 20 metres away in good daylight.
If you have a UK passport with a digital photograph, you can apply online for a provisional
licence (click below).
Alternatively, most Post Offices can provide the relevant application
form (form D1). When applying by post, you will need to provide an up to date passport
size photograph and identity documents along with your application and fee. Some
Post Offices provide a ‘check and send’ service for a small fee, meaning your documents
need never leave your possession (more).
“If you need glasses / contact lenses to satisfy the eyesight requirements,
these must be worn at all times when driving. If you have any concerns,
consult an optician before your first lesson.”
