I would urge anyone who is concerned about their loved one's driving to consider that most people remember the rules of driving but what changes with either just age or age and dementia is their visual field and reaction time. This is huge when driving. People with dementia will lose peripheral vision and eventually have only binocular or even worse mono vision. It is not a question of better glasses, it is failure of the part of the brain that interprets visual cues. The second thing that happens is a slowing of reaction time. If a small child runs into the street or a kid on a bike turns in front of them , can they see this and recognize what they see as a danger and can they get their foot on the brake pedal in time. Unless the neurologist has sat in the passenger seat of the car while the patient is driving, they have absolutely no way of knowing how dementia has or has not affected the patient. They only know what you tell them. I had to deal with this issue with my father years ago. He had no dementia but at 85 his reaction time was slowing. AAA had a CD called Roadwise Review, a tool to help seniors drive safely longer. Based on the response time tests on the CD my father could not react in time. Given this objective assessment, he gave up driving. Another thing to consider is your liability if your husband is found at fault in an accident.