Using the former verbiage implies that members of the Blind and Deaf community are “imperfect” and therefore cannot serve as valuable, functioning members of society. This cannot be farther from the case. They are not “lacking”, they simply perceive the world differently, and therefore we should treat them as such - human beings just like us, who just take in the world a different way. With decency and respect.
“Can’t see fully” honestly sounds much much worse than “can’t see perfectly”. I am not blind, but I certainly can’t see perfectly. Both are pretty stupid ways to describe blindness.
What’s respectful is describing disabilities accurately and still treating the people who have them like valid human beings who are as valuable as everyone else. Not treating them like fragile children.