Extraordinary! Anyone that is struggling with what must be by now the largest problem affecting the internet-age people: light from the monitor tormenting your overused eyes, must use this add-on. Brightness will stop being your worst enemy.
It is simple to use and a relief to the eyes.
Best of all, it almost never brakes a sites' redability obscuring elements of the webpage, like many other colour or style changing options do. At this moment the very best of what is in offer for this specific purpose.
:)