Take care of your eyes with F.lux
Probably you've experienced pain in your eyes after several hours of continuous use of your PC. The eyes get irritated and red because of the intensity of the light from the screen, up to headache can give you. It is well known that light can cause multiple effects on the body, from vary the circadian cycle (day-night cycle), our body temperature and even our appetite. There's no scientifically evidence in-vitro so far that explain this as revealed by this report of the Department of energy of the United States.
So although physiological damage does not occur by exposure to the light of the screen during the night, it is possible that bad habits, the intensity and the frequency of such exposure may cause other types of disorder arising later resulting in a biological damage, as those who work late in computers and tablets knows firsthand.
F.Lux acts by altering the color Temperature on your screen as well as the intensity to try and emulate the solar diurnal cycle in our town, in this way our brain does not perceive an abrupt environmental change, thus our eyes get not irritated and we can sleep way more relaxed.
During the day we perceive solar and environmental light composed by most of the spectrum waves, resulting in a high intensity white light. But by the evening and night, the short waves gets absorbed into the atmosphere and we only perceive the long waves in the range of reds and oranges, so F.lux alters the display temperature to emulate this situation.
F.Lux is not recommended for color accuracy work, or photographic retouch and video editing since it alters what you perceive, however brings options to disable it temporarily or even for a whole day. My experience also tells that it alters my settings and gamma calibration of the screen, making it in this sense a bit annoying and subject to improve.
Other than that, is hard not to recommend it!