I've gotten into the habit of modifying the CSS of web sites I frequent to improve the readability and usability in general. I do this using a plugin for the web browser. For instance, this is how the HN home page looks like: http://i.imgur.com/WaTQq.jpg This is the most perfect design because it's tailored to my needs. Here's how YouTube looks like: http://i.imgur.com/eZAsx.jpg Reddit: http://i.imgur.com/rnaxb.jpg
One of the big disappointments I've had with Chrome so far is that there's no way to set default font sizes (within the browser UI itself). I suspect there may be configuration settings .... hrm .... no "about:config", damn.
I'll try the userContent.css trick next. I've long forced all sites to use both my preferred fonts and sizes. Most comply reasonably well, though some (overly specified) designs break.
And that's for a guy who's been surfing in his 20s-40s, with good vision, though I'm just starting to feel the need for reading glasses. My parents are in their late 70s, Dad's got glaucoma. I've had to push up the contrast and zoom settings in his Mac account, for which he's grateful (the Web is one of his primary outlets / connections to the world now).
Sites designed on large, high-contrast Mac monitors, viewed on smaller, lower contrast devices, suffer the most. HN definitely could use a contrast improvement (I'm viewing zoomed up a couple of clicks right now, couldn't say just how much).
The real key isn't just sizing fonts (and setting contrast) appropriately, but to design pages which resize and rescale gracefully. I can live with the first if the second also occurs. Far too often it doesn't.
