There are virtually no benefits to having lived a long life, at least when it comes to getting discounts in Vegas. Unlike other cities that regularly feature reduced rates on everything from hotel rooms to meals for senior citizens, Vegas is pretty stingy when it comes to that sort of thing.
Some of the smaller chain hotels off The Strip (think Courtyard, La Quinta, Motel 6) will offer discounts to seniors and/or AARP members but at the big places on The Strip you'll pay the same rate as everyone else does.
Ditto restaurants and buffets where the thought of an early bird special would probably make most Vegas chefs gasp with horror.
Shows are the same story, with the only price variations are based on how good the seat is and not who is sitting in it (although some do offer discounts for children).
Attractions and some other forms of entertainment are really the only places where you can find senior discounts. Most of the major attractions, museums, and sights will knock a couple of bucks off admission for folks over 62 and you may find specials at some recreation facilities as well.
Other than that, Vegas is pretty blind when it comes to age and since it is a full-service, 24-hour town it can address just about any need you may have while you're visiting. Run out of a prescription? There are more than a dozen pharmacies on or within a few blocks of The Strip, most open all night. Having trouble getting around? Major hotels can arrange scooters or wheelchairs with very little notice.