For past sometime, Google Reader were experimenting with a simple CSS-based lens that allows the user to selectively magnify the current article, which was prototyped using AxsJAX framework. The CSS-based lens or J-walking is subtly different from using a generic screen magnifier, that end up magnifying the entire screen. But Google Reader lens is smarter; since it knows which article you are currently reading, it can selectively magnify just that article upon request. This results in much better use of screen real-estate -- something that is an even scarcer resource when you're a low-vision user.
Google Reader has now integrated this functionality into the main Reader interface. So with this lens in hand (your pocket) you can continue to hit j and k to move through articles, and when you find the print too small to read you can press = or - to enlarge or shrink the font of the article you're reading. The C in CSS stands for Cascading -- and in this case, you the end-user get to have the final say in how you consume your content by cascading your request for a larger font on top of the presentation chosen by the content publisher.
Google, Google Reader, CSS, Maginifier, New Features