Last week Facebook started rolling out the new Lightbox photo viewer. However, many users have been less than enthusiastic about this change. Two methods to get back to original photo viewer includes refreshing the page when Lightbox loads and removing &theater from the URL. However these are not permanent solutions.
Internet Explorer users, should see this to disable the Facebook Lightbox Photo Viewer in Internet Explorer.
If you want a more permanent solution, there are extensions for Google Chrome and Firefox. For other browsers though, you probably have to stick to the manual methods mentioned above.
Facebook Lightbox Killer (Google Chrome)
If you are using Google Chrome or Chromium, click on the link above to download and install the extension. Once the extension has been installed, it will automatically open the photos in the original viewer not Lightbox.
Facebook Lightbox Killer (Firefox)
Firefox users can click on the link above to install the extension to disable the Lightbox viewer. However, if you use Firefox 4.0, you probably have to wait. At the time of writing this, it is available only upto Firefox 3.6.
Here is a screenshot after I have installed the extension on Chrome.