Graphing calculators are starting to become a huge issue. While accessible graphing calculators do exist, they cost ten times more than the standard inaccessible ones. Also, they work quite differently, so the blind student often has to muddle through on her own, because the instructions the teacher is giving the rest of the class are inapplicable to her.

I'm assuming you're asking about high school; in university, the challenges are much different.

For maths, at a more advanced level, university on, the main problem is being able to read formulae. A lot of mathematics is typeset through LaTeX into PDFs which are not accessible for screen readers in this regard. Obtaining LaTeX sources from professors is sometimes a workaround, but it is not viable when one is doing any kind of independent research.

A lot of maths on the web is likewise inaccessible. It's often presented as images, or SVG, or the like. MathML is somewhat usable if not all the way there yet.

The two things that would make life a lot easier in this regard would be:

* Improving LaTeX's output to make the PDFs it generates usable with screen readers.
* Improving MathML handling in browsers and screen readers.

For science, most educational software is very visual and not usable with screen readers. Lab equipment is quite uneven: sometimes it's possible to drive it, sometimes not.

I used to be a geology major. I also was a geology TA. I think the biggest issue for me was not having instructors that knew how to teach beyond the visual senses. Having a lab assistant that knew how to describe things beyond color/shape was a huge assset, and I actually lab assisted for several completely blind students because I knew how to describe rocks by feel/sound/taste.

I have always had to spend more time on these two subjects, they are the biggest visual challenge for me which is unfortunate because they are my greatest interests. In subjects like Biology I had major issues using microscopes because (at least on the models at my school) I had to remove my glasses in order to even get an image through the optics. This proved to be pretty counter intuitive because I couldn't see what I was looking at.

I also struggled with dissections and identifying parts we were looking for. I did much better in Chemistry because it was much more conceptual, I could look at stats and formulas and grasp it.

In math, complex formulas can be problematic. My techniques involve using my CCTV and handheld video magnifier to get contrast and magnification correction on the media. If possible I do everything I can on the computer which can read to me and blow everything up to the level that I need it to make it visible.