I'm in the [very] early stages of devising a plot for Redstone's Accessible Future contest. I haven't actually written a differently-abled character before, a fact I'm frankly rather ashamed about (another failure is my lack of coloured characters) so this contest is firstly a challenge to myself.
What I want to avoid is a plot that is "positively discriminative", because I believe that would imply a negative difference in ability. That disability is something to make allowances for, rather than accepted as fact.
It's not even a case of "disability" when you're dealing with science fiction - just think of the different forms of aliens that could be encountered. Non-humanoid aliens that might not have legs or other limbs. That have different senses.
The question is - do I make it obvious that such things are accounted for, or would that negate the point of the challenge?
As I've been thinking about this aspect, one of my favourite sci fi shows has come to mind. In Farscape, the main ship has ramps between floor levels, a natural occurence since she's a biomechanoid, but something that makes her accessable for all species. It's never mentioned, just there.
And I think that's the tone I want to aim for.