A few years ago I had a legally blind student in my art class. She could see and read things with the help of a large square magnifying glass that she carried with her.
She could read her watch, which had the largest face I have ever seen, so she sounds a little less impared than your student.
I had the students look at special needs artists and try doing mouth painting etc to understand what this gal had to go thorough. We also painted one day with scarves over our eyes. I think this helped her classmates problem solve with her and I. They were great and always trying to help her out. I even took my contacts out at home one night and tried painting and ended up with paint on my nose and a very interesting painting.
Monet was one of the artists we studied by the way as he was going blind by the end of his life.
Anyway this student did well with bright colors and large surfaces to work with. She also seemed to enjoy textured paints and surfaces. We tried various different things like painting with shaving cream and sand painting. (painting with various grades of stuff in different colors-sand, corn meal, pebbles etc..) We even did "nature" painting. One of the students came up with the idea of finger painting with berries mud etc.
She ended up being one of my most creative students and her classmates loved her. I think she gave them permission to big, bold, messy and to have fun.