Glasses for the legally blind can benefit them in other ways beyond eyesight. I'll leave further explanations to people who know more about this than I do.
I came here to say that my local newspaper recently did a big story about a young adult woman in the region who has a serious chromosomal deletion that has left her functioning at the level of a preschooler; she can walk, talk, feed and dress herself, and is toilet-trained but that is about it. They found out that she had metastatic breast cancer, and had several clinics flat out refuse to treat her because the family is insisting that Everything Be Done even though she doesn't understand what is happening to her, beyond "You have an owie on your chest, and the treatments will make you not feel good". Most of the doctors just wanted to do surgery, with radiation as comfort care, but her parents don't want just that done, just because she's mentally disabled.
C'mon, this isn't for you, it's about what's best FOR HER.