I want to point you to a collection of resources for teaching the visually impaired. The site Teaching Math to Visually Impaired Students is put up by Susan Osterhaus, who has been teaching math to the blind and visually impaired in Texas for almost 30 years.
I have never even heard of many of the techniques and materials she refers to on the site, like Nemeth Code and Thermoform Tactile Diagrams. I wish there was a little more explanation of what these things are, but I am perfectly capable of searching on the Internet(which is what I did). Nemeth code is a special Braille used for math and science notations that allows arithmetic calculations, algebra, trigonometry, calculus, etc. There are a variety of Thermoform Tactile diagrams, but the general idea is that these are diagrams where the lines and curves that create the diagram are raised on the paper. Some papers are available where you can draw on the paper with black markers, and after running it through a copy machine, the lines become raised (the technology is based on light absorption). This would certainly be a great option for 2-D graphics.
I have seen a machine that will make tactile 3-D graphs – when I was in Kentucky last year. More to come …
