If you go in & override the site's specified font with your browser, you'll do it for other sites too, and that
could be problematic. Additionally, you're probably correct that changing the font (on your computer) doesn't mean you'll (be able to) change (over-ride) the (absolute)
size of the font as well. Your browser will probably default to the CSS specifications on the individual web page when it comes to the size (in px or pt).
I'm also noticing that a lot of the eye strain I see here, is indeed because of the contrast. The (entire) background is nearly white. So your iris cranks down because of the overall brightness, making it harder to (clearly) see the text. But it's hard to say if other (color) schemes would be better (or worse
), without actually seeing them.