It should also be noted that making a site usable in textmode non-js browsers also tends to improve the usability of the sites for blind users. And trust me, there's a lot of those folks out there, and they all surf the web. [Ref. here]
As I am fortunate to be not visually impaired, I cannot judge the accessibility of the Stack Exchange for those who are. However, I do see the fundamental importance of it. Therefore, I would like to use this opportunity to start a discussion on this topic by the following question:
How difficult is it to access the content of the Stack Exchange network for the blind and visually impaired and what can be done to improve it?