Are you on chrome? I just opened in firefox and it is easier to read. There may be multiple factors here but I have issues with some fonts in chrome being nearly unreadable without increasing font in browser until they essentially present as bolded.
Chrome needs text-shadow to start with
0 0 0 transparent,
or it will mangle the webfonts. I don't know why they still haven't fixed this.
I have trouble with it at the sprightly age of 33.