About the Eyesight Check
Before you can start the driving test you must demonstrate that your eyesight is good enough to be able to drive safely. You do this by reading a clean number plate of the old style from a minimum distance of 20.5 metres (approximately 67 feet or 5 car lengths). If reading a new style number plate (these letters are narrower) you must be able to read it from a minimum distance of 20 metres (approximately 66 feet).
If you have difficulty with spoken English you are permitted to write down what you see. If you need to wear glasses or contact lenses to achieve this, you will be required to wear them throughout the test and whenever you drive normally. If you cannot read the number plate the examiner will ask you to read a second number plate and if necessary take you a little closer to just over the required distance.
If you still have a problem the examiner will then measure the exact distance and check your ability to read a third number plate. If you cannot read this third plate correctly you will fail your driving test and the test will go no further.