It began with a friend who was in the job market as a 50+. More on the hardware side. This guy has some cool experience. He gets lots of interviews, they go well, but no offers.
As his frustration grows, he grows desperate to try something different. He dyes some color back into his hair, gets some tinted glasses, and lets his daughter take him shopping for some more hip interview clothes.
A month later and he's in bidding wars for who to hire him. He said the difference was night and day. He was now pointing out his age in interviews "are you sure I'm not too old?" and the interviewers were like "no way man."
I wondered how one off this was. A year or so later, knew another guy who was having this same struggle. We shared the story with him. He raised his eyebrows, hesitated for a week or two, the colored his hair, got his niece to take him shopping. And pretty much same thing.
Obviously, this is a small sample set. But the lesson I took from this (and haven't had a chance to prove for myself yet) is that it's not your age that will limit you, but your apparent age. If you are old, but look like a younger/fresher version of yourself, you do well. If you appear "old", you struggle.
Best of luck.