I have family like this. They can see enough 'shape' to play something like Tetris extremely well but anything that relies on colors is usually a no. When we were young they had color but that went away first. My understanding is that as they get older the resolution of the shapes gets lower and lower, so they have to make things bigger and be as close as possible.

It was beyond the point of glasses being able to do anything useful for them just as they finished college.