Rethinking Partial Sight

I had never considered "figurative blindness" before, or a rethinking of partial sight, but I felt like I learned something I should have known or at least considered before today. The notion of a space that is situated between vision and no vision seems murky - how does one institute a Design Research Project off of this space? And yet I now understand that without the resources to address the aspects of partial sight, including that such sight may deteriorate over time, it isolates these individuals and can bring with it depression. The need for designers to have empathy, to contribute rather than react, to create graphic and textile communication seems imperative, but the one aspect I could not find in the reading was the specific action they took to address it - what, other than books on tape and corrective devices - does the partially blind person use to bridge this gap? I kept reading for the exact specifications of what they had used to design for multiple communication devices, and didn't find it. That was the only aspect of this piece that disappointed me, because it did seem that they addressed the issue - but I am still not quite sure how....