I didn't really "get" the purpose of flux for a while. I appreciated the sleep schedule reinforcement aspects of it but if you don't have a normal sleep schedule then it would seem to be less useful. That's always been the major selling point for f.lux forever, and it seemed so intrusive so I didn't use it.
However, I finally figured out the real reason for using it: white balance adjustment. The thing is, our eyes aren't just imaging sensors, they're active systems that continually adjust to ambient conditions. They do lots of things without us even thinking about it. One of the most important things they do is compensate for white balance. If you look at a white wall when the sun is shining on it during the height of daytime and if you look at the same wall during the middle of the night when it's illuminated by artificial light you will perceive it to be the same color in both instances. But in reality it's not, when lit by indoor lighting it's a very different color, but our eyes/vision system automatically adjust for the different spectrum of lighting.
The problem is that computer monitors throw a monkey wrench into this because they are independent light sources. White displayed during the day on a computer monitor is #FFFFFF, during the night it's still #FFFFFF, but this conflicts with the white balance of the environment. And that conflict causes eye strain and discomfort. At night looking at your monitor you might even perceive white to be slightly bluish, due to the conflicting white balance. By bringing the white balance of your display into harmony with the changing white balance of ambient lighting (as it transitions from natural to artificial) you get rid of a lot of those problems.
Hopefully with f.lux adding more configurability into their program they can make people more aware of these benefits regardless of sleep patterns.
However, I finally figured out the real reason for using it: white balance adjustment. The thing is, our eyes aren't just imaging sensors, they're active systems that continually adjust to ambient conditions. They do lots of things without us even thinking about it. One of the most important things they do is compensate for white balance. If you look at a white wall when the sun is shining on it during the height of daytime and if you look at the same wall during the middle of the night when it's illuminated by artificial light you will perceive it to be the same color in both instances. But in reality it's not, when lit by indoor lighting it's a very different color, but our eyes/vision system automatically adjust for the different spectrum of lighting.
The problem is that computer monitors throw a monkey wrench into this because they are independent light sources. White displayed during the day on a computer monitor is #FFFFFF, during the night it's still #FFFFFF, but this conflicts with the white balance of the environment. And that conflict causes eye strain and discomfort. At night looking at your monitor you might even perceive white to be slightly bluish, due to the conflicting white balance. By bringing the white balance of your display into harmony with the changing white balance of ambient lighting (as it transitions from natural to artificial) you get rid of a lot of those problems.
Hopefully with f.lux adding more configurability into their program they can make people more aware of these benefits regardless of sleep patterns.