How is your eyesight and especially peripheral vision? How quick are you to react? Those are some of the problems you face as you get older,and aren't as used to it. If glare bothers you much, you will need to deal with it, unless you do local and the driving time is always during the day. I started at around 50, and there is a bunch to learn to see that might be more difficult now. You should learn to see much more than you are used to driving a car or a straight truck, and if you feel old on any given day, that is when you could have problems. The big carriers probably wouldn't take you even as experienced, the smaller ones are up to the insurance companies. A guy I know who was still pulling tankers in his early 80s, went to Schneider when he was in his late 60s with a prehire, and safety sent him away, he was too old for them to consider allowing him to drive for them. I haven't talked to the guy in over 8 years, but he was young for being in his mid 70s then. Another guy I know much better, having hauled poultry with him for years, hung it up at 77, he had a bad trip and with his other health troubles, he acts older than his age. I still hear from him.
More and more companies are starting to use 65 and 70 as a cut off age. Prolly has to do with their insurance carrier.