This is so frustrating, and so representative of the conundrum that is ‘invisible’ disability. In fact, the reason that I use quotation marks around ‘invisible’ is that our disabilities are never really invisible; they just don’t look the way abled people think they should. Sooner or later, our disabilities make themselves visible, but because abled people don’t recognise what they are seeing, they assume that we are somehow morally deficient. (Not to get too off-topic, but in a weird way it echoes the ways in which disabilities of all kinds were perceived as divine retribution in pre-Enlightenment Europe.) So we are faced with the choice of being judged as either lacking in character or lacking in capability (the usual prejudice faced by visibly disabled people).
For my part, because I like tilting at windmills, I’ve taken to mentioning my disabilities in my resumes and cover letters, with emphasis on the unique skill set I’ve developed as a result of my experiences as a disabled woman. Of course, it’s worth noting I’ve had rather more responses to the applications where I haven’t mentioned it ;)