Clear view
Eventually I got the right glasses, after two months of discussion - woho, much better contrast than before, as the old ones weren’t focusing enough light onto my eye. I can see cleary now :) Moreover, I found an excellent editor font (Monaco) at the Programmer’s Notepad Blog.
I’m much more productive with this font than with plain old courier, as it looks very friendly, is easy to scan and very easy to watch at, especially with larger code blocks as it’s not too thick and heavy. I’m using it currently on Windows at a font size of 10 pt and “Clear Type” anti-aliasing enabled.