So people who previously said "I'm blind and need accomodation" now get put in the same category with people who say "I have visual acuity spectrum disorder" because their vision is 20-40.
Uhhh... That category already exists. It's called visually impaired, and it does receive special accommodations. Back when I was in school, one of the girls in special ed had coke bottle thick glasses. She got treated by pretty much everyone like the other kids in special ed. Not too much bullying (though some), and mostly they just got socially ignored, but basically as far as everyone was concerned she was a **Slur Deleted** along with the rest of the kids. Her only disability though was that she was legally blind. Even with the glasses, she needed large print, etc. These days, she probably would not be thrown into special education classes, she would probably be in class with everyone else and just get help with reading materials, what the teacher writes on the blackboard, etc.
Now, of course, that is a spectrum as well, and you can argue that there are people whose vision is not that bad who are getting accommodations they don't need. However, it makes more sense to err on the side of caution when making the cutoff. You may complain about it being unfair to everyone else for someone you don't think deserves an accommodation to get one, but it's a lot more unfair for someone who really needs one to not get one and essentially be cast out.