Disability studies is of universal import: Every human being is fated to become disabled (if they don't die first). Moreover, every teacher will, in their time, teach countless students with mental or physical disabilities – and will therefore have classrooms full of abled students with disabled classmates; abled students who can be persuaded, through the magic of the lens of disability, to better put themselves in the shoes of said disabled classmates.
Disability is common in texts, and, almost as commonly, a shorthand for – i.e., occurs in a character in conjunction with – something else, usually something negative – villains are disabled more often than heroes.
Disability can, most obviously, include physical disability, such as, most commonly in popular media, missing limbs – e.g. Star Wars (It can accurately be observed that over the course of George Lucas’s six Star Wars movies, Anakin Skywalker/Darth Vader loses five of his four limbs), How to Train Your Dragon, Harry Potter, and virtually any text focusing on pirates (peg legs, eyepatches, and hook hands being de rigueur in such texts).
Disability can also include mental disability, which is perhaps more common in the traditional literary canon – e.g. Of Mice and Men, One Flew Over the Cuckoo's Nest, and Flowers for Algernon.
What, one might ask, of mental illnesses, such as sociopathy and/or psychopathy? Are they disabilities to be accommodated? What does it say about us as a society that ‘he's a psychopath’ is so often used as the entire characterization of a villain – e.g. the Joker from DC comics and movies?
The lens of disability can lead one to ponder subjects that may prove important in social and legal spaces – is genetic discrimination, as one sees in Gattaca or X-Men, fair and reasonable, or is it good that laws have been passed prohibiting it, or should those laws be strengthened?
What of people with increased ability relative to human average, such as in superhero media (including, again, X-Men)? Is it fair that Michael Phelps is some sort of super-powered swimming mutant? Should such people be brought down to human average – or even, should everyone be brought down to a minimum, so that everyone is truly equal, as in “Harrison Bergeron”?
A disabled lens can bring students to understand more about their own minds, may bring better understanding of disabled peers, and may lead to slightly better lives for the disabled among us – in my experience, many problems faced by disabled people result less from overt ableism than from people simply not thinking (which, of course, has ableist results). The classic example is the maintenance guy who chooses to shovel snow off the stairs before shoveling the ramp, not pausing to think that a shoveled ramp is usable by all students while shoveled stairs are usable only by able-legged students. Perhaps if the maintenance guy had studied critical disability theory in his ELA classes, he would have paused for that thought.
See Also
Critical Queer and Disability Theory in the Secondary English Classroom