A lot of people assume blindness means absolutely no sight whatsoever, which isn't true, because quite a large number of legally blind people have eyes that detect some degree of light. Temporary blinding from illness/injury exists. Flashing a bright light into someone's eyes, rendering them momentarily unable to see, is also a very valid and very old usage of "blind" in the English language. Being metaphorically dazzled by something and temporarily unable to respond ties in with the latter meaning and goes way back in its usage.
Paralysis has a similar scale. Many people assume total lack of movement, and "only" having one's lower body unable to move doesn't even immediately register as paralysis in the mental image a lot of people have. People with severe mental illnesses like depression and some forms of schizophrenia are rendered unable to move (it's not a desire to stay still). People can also be temporarily paralyzed through poison or mental shock (as in they literally, physically cannot move out of fear).
Words have range. Context makes their meaning precise. I really hate to bring this word in here, but denying someone with a mental illness the right to use a word is because it's not "real" enough compared to another person's struggle is "gatekeeping". Suggesting words they use to describe their illness is "insulting" is harmful to them.