As people grow old they begin to become a bit decrepit. Normal everyday tasks can present dangers of heart attacks, strokes or a broken bone from a fall. The pull of gravity puts so much strain on the elderly that many lose almost all of their independence for fear of being killed by the pull of the Earth.
Fortunately, though we may not control gravity there are places, that will come within reach, where gravity is not such a predominant force. The the closest is the Moon.
So here is the opportunity. Within the next 50-100 years space entrepreneurs have the chance to create a retirement colony on the Moon.
On the lunar surface the gravity is 1/6 that of Earth. There would no longer be the danger of falls or strains on the hearts of the residents. They would be able to live independently, almost as they had before they aged, being able to do their own chores, walk, and even run.
Now the question is why is the Moon ideal for such a structure? Why not just put people into orbit in a large space station where there is zero gravity.
First, the change of going from gravity to zero gravity permanently, can be a large strain on such elderly bodies. The deterioration could be too extreme as the body adapts to the environment. There is also a learning curve for operating in zero-g. Floating and navigating in a weightless environment takes skills, reflexes, and coordination that the elderly may no longer have. The gravity of the moon doesn't require people to change their habits. They can still walk and run, it will simply be easier. The Moon is also within communications range of the Earth so the tenants can still remain in real-time contact with their families and friends.
The Moon will also offer the advantage of unlimited ways to spend time. Hikes, tours, sports and other activities the cannot be performed by the resident on Earth or by a space station in orbit are available on the Moon. What better place to retire than where there is always something to do and is continuously beautiful.
The last reason to use the Moon is that the retirement center can be made more cheaply and safely on the Moon than in orbit. This is due to the fact that the Moon will have a construction infrastructure that will be able to build and expand facilities using the materials on the Moon. So instead of having to launch everything, for the center, from Earth, as in the case of the space station, it can be manufactured on site. This infrastructure also makes the facility safer than any orbital facility could be. If a leak is sprung, the residents could be moved out into new spaces, that are constructed, or share with other colonists, in an emergency. A space station does not have this luxury of places to go.
Now for the dangers of such an endeavor. Space medicine is still unclear as to the complete affects of low gravity on the human body, and it is completely unknown what it will do to an elderly body. While the physical abilities will be improved internally we don't know what can happen. Low gravity can cause the bones to give off huge amounts of calcium into the body which form kidney stones and other ailments. Who knows what this type of thing would do to the elderly body.
space elevators can become feasible in order to create a gentle journey.
Overall, the idea of a retirement community on the moon is one of the riskier endeavors to attempt with the technology we understand today. But it is feasible and potentially very lucrative with the advent of cheaper launches and bases on the Moon. While it is still decades away current doctors and engineers can work to create the medical needs for such a concept today.