I found this program the other day and thought I would pass it on. It gradually changes the color temperature of your monitor based on time of day,Long. Lat. coordinates, and type of lighting. At first I really didn’t notice any difference but after staring at a screen without f.lux and then coming back to mine it really stuck out to me how much more gentle on the eyes my screen was.
There is a setting for “slow” color change which I recommend over “fast”. This just makes the color change more gradual throughout the day so you really don’t notice it.