As anyone with an ebook reader with an eInk screen knows, there is no backlight in these devices. If you want to read in low-light conditions, you have to provide an external light source. There are a multitude of clip-on book lights available, and someone has naturally developed one for the Kindle from Amazon.com. The Kandle is a low-profile, wide-format light in white plastic. It has 2 LEDs and comes with batteries for $25. It works with all the Kindles, and Amazon.com says it works equally well with other ebook readers, including the Sony readers.