If you are applying for your first provisional licence, you must submit an eyesight report with your application. You can download the eyesight report form (D.502) from here.
If you are renewing your licence and there has been any change to your eyesight since you got your last licence, you must go to your optician or a GP who will supply and fill in the appropriate form to say whether or not you need glasses for driving.
Your driver’s licence will then show this information. This means that if your licence says you need glasses for driving, you must always wear them when driving or you will be breaking the law.