The issue is antialiasing, or the lack of it.. you can fix this using a .fonts.conf or by setting
Xft.antialias: true in your .Xdefaults/.Xresources file.
Code:
<?xml version="1.0"?>
<!DOCTYPE fontconfig SYSTEM "fonts.dtd">
<fontconfig>
<match target="font">
<edit mode="assign" name="antialias">
<bool>true</bool>
</edit>
</match>
</fontconfig>
Good luck.