My dad called me this morning to tell me he was in a car accident on Friday. Thankfully no one was injured and the accident occurred at very low speed but it was clearly his fault, as he rear-ended the car in front of him at an intersection. He told me that it was very sunny out and that he thought the car in front of him had completed the turn, when in fact they were stopped. Should this be worrying? He is 63 and I haven't yet noticed any signs of memory loss or lack of concentration/focus but I can't bear to see him be a potential danger to himself. Should I force him to get an eyesight/focus checkup?