That's about what I was asking - for myopia, this would be the difference between glasses (technical assistive device) and Lasik (correcting the biology). I think it's unrealistic to assume that medicine won't progress. A lot of physical disabilities that are now a major factor in a person's life will probably, in the future, be a minor annoyance or therapies will exist to give people full functionality. There may be people who choose not to have such therapies, but in many cases in the future the decisions will be made by (able-bodied) parents or by people who became disabled after being able-bodied - both of these subsets of people, I believe, will be much more likely to choose administering the therapy rather than preserving the disability. Myopia's actually a good example, since before glasses were invented it impacted people severely, then moderately, and now laser surgery's improving in leaps and bounds, clearing the way to eventually having, say, 99% of myopic people correcting it as soon as their eyes stop growing. (Mind you, I'm saying that as a myopic person who is waiting for the surgery techniques to improve in reliability.) Even if there are people on whom these therapies do not work, it will translate into a much smaller portion of the population with a given disability. I believe this is already at work in the deaf population, with a subset refusing hearing aids, but a lot of people opting for implants, especially when deaf children are born to hearing parents?

What I would like to see in SF would be new disabilities. There are bound to be traits that do not impede functionality now, but will impede it in the future, like the inability to see 3D images. New mental disorders, quite possibly, maybe something else entirely?