How can I make Firefox more low-vision friendly?

I want to use Firefox since it allows me to use Adblock Plus. But I am legally blind; and, despite the zoom features, Firefox is still not as easy for me to use as Internet Explorer. So, this leaves me having to choose between security and usability. The one thing that I cannot get used to visually is Firefox's address bar display. With all the black and blue text and the fact that it seems more "jumbled" to me than Internet Explorer, I find it very hard to use. Is there any way I can tweak the way the address bar is displayed (by changing font size, color, content, arrangement, etc.)? Thanks!