This is a tough question and I hope I can answer it with dignity (although I make no promises about spelling errors).

There are several reasons and the first is that I don't feel disability is ever handled properly in the fantasy or sci-fi genres. Either the disability grants magic new abilities, which is pretty insulting, or a spell can fix hundreds ways someone became disabled, which is also rather insulting by ignoring both the cause and the actual effect (retina problems? cancer? Missing eyes due to surgery or injury? How does one spell fix all of that, and that's only going by the cliché that all blind people are completely blind). Or it's never cured or addressed, but people act as if a cellphone for sighted people somehow cures it because it's a wonder of magic/technology. I find it hard to read or watch anything in those genres when disabilities are addressed. And that's visible disabilities.


Another is that I'd like to actually show a transition. Even a sudden injury (which is what happened in the story) requires learning new skills and coming to terms mentally and emotionally. I don't recall a single show or story that showed much in between a character becoming blind and then fully adjusted. At best you get a few shots of paper bills folded differently like in the scene in Daredevil. You might as well have two different characters sometimes. If the story is not showing, then the reader is not learning, and thus they aren't understanding anything as either someone who is blind or as an outsider figuring out how to interact with someone at any stage of the transition.


The last reason (that I can think of) is to dispel stupid ideas about the disabled. I'm diabetic. Too many people think I'm faking, insist that I'm lying because I'm not fat, treat it likes it's the end of the world (people are shocked that bread isn't some miracle drug), ask stupid questions (sometimes behind my back) like if I have all my toes. And so on. It's easier to address a more obvious disability to the ignorant (super apologies for being offensive). Unless someone has no vision at all, blind people can do anything sighted people can; some can even tell you if that shirt you're wearing is ugly. But this isn't a PSA. How characters in the story perceive and act around someone with a disability is part of their character and thus part of the plot. Showing bigotry and the willingness to learn and stupidity and actually knowing how to treat someone different can show a lot about them.


Disabled people are part of the world and using a story can sometimes be easier to convey that to others than using a rant.

If that's all wrong and mean, I don't want to write any of it and I want to know what I should write instead.