My elderly mom sleeps too much. Any suggestions?

My uncle is 84yrs. If there are no appointments for the day I let him sleep as much as he wants to, I figure he was in the military for many, man years (you know how early they get up) so now at his age he deserves to sleep as long as he wants to.

Oh those darn blood pressure meds. My cardiologist had to experiment with different doses before we found one that didn't make me fall asleep with my head on the computer keyboard :P

Also I found if I have days off from work, I find myself napping numerous times during the day, not quite as bad as prior to the meds being adjusted. Especially after lunch and dinner, which is common as we age [I am in my 70's]. I had to find something to keep me busy. Would your Mom be interested in doing a family tree? Find old photos of people you don't know and have Mom write on the back the names in the photos. Oh how I wished I had thought of that when my folks were still around. I have too many photos where I am saying "who are these people?".

What is your definition of too much?
Lots of older people nap, sometimes because night time sleep is less restful. It is also fairly common to fall asleep when we are unable to find meaningful ways to occupy our time. Can you share why you are concerned?