The knowledge of a patient’s visual acuity and how this may impinge on their driving ability is a confidential matter and may not be disclosed to a third party. If a patient is suspected of being below the legal standard for driving, s/he has a legal responsibility to inform the DVLA. Any advice which you give to the patient should be noted on the record. In the first instance talk to the patient, advise them they are unfit to drive and try to persuade them to stop. Remind the patient that s/he is legally responsible for informing the DVLA or DVA if they do not meet the vision standard for driving. However, if the patient has told you that they will not stop driving, you may conclude the public interest outweighs the duty of confidentiality.You may wish to seek the advice of your professional body or the prescriber.