This. When I'm working at night on my desktop or laptop, I'm using f.lux. When I'm browsing the web late at night, I have my brightness set as low as it can go, and invert colors. Unfortunately the flickering of changing pages, images, etc. and going from a page that has a white background to one that is black (which shows up as white inverted) still wakes my wife up, so when I anticipate flickering, I have to hide under the sheets to read like a little kid reading past his bedtime.

Further, the minimum brightness on iPads is still blinding. You have to download a specific "night browsing" browser just to get it to go lower, and if you are in an ebook reader, you are reliant on them having something to help.

Ultimately, I found that for ebooks I'm just way better off with one of the new Kindle Paperwhites, which I'm absolutely in love with. However I still find myself wishing that they had a native way to invert the colors of text. This is trivial to do with common ebook/text doc formats, and I really wish they'd make it an easy "night reading" feature. Having the entire screen with a white background causes unnecessary eye strain and brightness when reading at night. Reading white text on a black background is SOOO much easier on the eyes in a low-light situation.

Taking it a step further, while I hate backlit screens for night reading, one of my favorite reading setups is using a "terminal green" on black in Stanza on my iPad. Now if only the Kindle Paperwhite could do color...