Also, people generally sleep fewer hours per night as they age. As a result, they have more free hours per day as they age. "Sleep deprivation" has a very different meaning for the young and the old.
Actually, there is some evidence that sleep needs remain the same for older people while deep sleep becomes more difficult to achieve and easier to interrupt.
I wonder what "needs" means, though. As I get older, my body just naturally sleeps fewer hours than when I was younger, and there seems to be nothing I can do to change that. I don't use an alarm clock, I go to bed at around the same time every night, I don't consume caffeine after noon, etc. When I wake up in the morning, I feel awake, and it's almost impossible for me to fall back asleep, even if I continue lying in bed with my eyes closed.
So, scientists may say I "need" more sleep, but what of it? I can lie in bed awake feeling bad about that, or I can get out of bed and do things with my extra time every day. I try to live a healthy lifestyle, and I would definitely sleep more hours if I could, but I've followed every suggestion, and my body just does what it wants. My impression is that this is a common experience.
