Get Rid of the New and Annoying Facebook Image Preview is a long name for a Chrome extension, but it's certainly self-explanatory. If you're a Chrome user and aren't too fond of the latest update to Facebook's image viewer, this extension will bring the old viewer back.
There is hardly anything you have to do to make this work. Just install Get Rid of the New and Annoying Facebook Image Preview and go to a Facebook image gallery. When you click on an image, the plug-in will load the old-style version.