Ask HN: How do blind people code and work with terminals?

In the space of half a day, vision in my right eye deteriorated to the point that I can't even see an eye exam chart with it. I've already gone to the hospital and going back tomorrow for another round of tests. It's not a tumor, no signs of MS, no signs of infection.<p>I know they're are people considered legally blind that still write code, so how do they do it? Is there an OS that's better geared for accessibility, and are there any tools that can help make life easier?