I know some FlyerTalkers have been involved in supporting NGO Orbis in its global ophthalmologic surgery and teaching mission.
We are an international non-profit bringing people together to fight avoidable blindness. With our network of partners we mentor, train and inspire local teams to fight blindness in their own communities.
FedEx recently donated an MD-10-30CF (DC-10-30 freighter upgraded to MD-11 cockpit and converted to a freighter is comparable to the MD-11 to the point pilots are certificatied to fly both) to Orbis. FedEx Aviation supports and maintains the aircraft and 18 FedEx pilots volunteer their time flying it.
The MD-10-30CF contains everything from seating for passengers or students coming to observe eye surgery on state of the art video equipment to high tech operating room space, cargo modules that provide power, purified water and medical grade oxygen.
See more about Orbis here:
https://www.orbis.org/en
and an Aviation Week illustrated page about the new Flying Eye Hospital aircraft
here.