I have been having a hard time seeing the difference between an 'a' and 'o' in my code recently and decided to find a different font. After searching around the Internet, I found Inconsolata. While looking for a good source I found a version with strait quotes that is quite pleasing.

You can read more about it on this site or just do a search for Inconsolata-dz:
http://nodnod.net/2009/feb/12/adding-straight-single-and-double-quotes-inconsola/

I also changed the theme of my Microsoft Visual to a dark background.

Both the font and the darker background make a huge difference to the readability and less eyestrain to code. I highly recommend spending a little time tweaking your dev environment so that is comfortable for you.