An Oblique Approach
I've just been reading the 'An Oblique Approach' sextet by David Drake and Eric Flint and disability crops up a few times, one of those instances being fundamental to the plot.
The novels are SF, but set in the Sixth Century AD using a core cast of historical characters, and revolve around two forces from the far future attempting to alter the way humans and human society will evolve by changing the past.
The bad guys are essentially fascist eugenicists who don't want humanity to stray away from the traditional human form and are much into rigid top-down control with everyone knowing their place, so they have chosen the Malwa Empire in India as their puppet, intending to make the rigid Indian caste system the sole future for the human race, while stamping out Western individualism and competence driven society before it can become dominant. The good guys have chosen to work through the Byzantine (Eastern Roman) Empire as that's a clear example of competence and individualism rising to the top, Emperor Justinian having started life as a peasant. The protagonist is Justinian's general Belisarius (Justinian unfortunately being a paranoid control freak), who really was one of the best generals in history, aided by Justinian's wife Theodora and his own wife Antonina (both of whom started out as courtesans -- it was an interesting time). Helping Belisarius is an artificial life form called Aide, which takes the form of a crystal, while the bad guys are run by a more traditional computer complex called Link.
With several of the most powerful empires on the planet engaged in massive military operations, there are inevitably casualties and characters who become disabled; Justinian is blinded in a coup attempt (this was common in the Byzantine empire, a blind man wasn't allowed to be emperor), as is a younger aide to Belisarius and another Roman general loses both legs, becoming the reason for the invention of the wheelchair (by Justinian). It wasn't unknown for blinded nobles to remain politically active, but to have two military officers continue in support roles (one running logistics, the other communications) after becoming disabled is unusual. But ultimately all three are really only secondary characters. More fundamental to the plot is that the bad guy, Link, operates by possessing a member of the Malwa royal house, and the conditions for that possession are ultimately revealed to be that they are female (not really explained clearly beyond hereditry) and that they have autism. So we have a fascist, eugenicist state operating through the possession of girls with autism, which is an interesting contradiction. Looking at the structure of the narrative, autism was probably chosen so that there are only a limited number of candidates for Link's possession, but there may also be a perception at work that people with autism are 'vulnerable' or even computer-like -- it's just enough to make me not entirely comfortable with the narrative, though obviously the narrative is positively intended to make normies slightly uncomfortable due to the exploitation of someone they would classify as 'vulnerable'. OTOH, any book which makes eugenicists the bad guys is all right with me!
At six books in length I wouldn't suggest reading them unless you're a fan of alternate history or time travel, and of long sagas, but if you are then they're worth reading. The first four can be found in the Baen Free Library at http://www.baen.com/library/ all six are available at http://baencd.thefifthimperium.com/ in various of the Baen CDs.