On AND off
Depending on the mood, the time of day and on what I am doing. Editing a photo gives a better result with no True Tone (or Nightshift)
But I have a troublesome relationship with both of them. Sometimes my eyes feel relieved when switching it off, sometimes when switching it on. Maybe it depends on the amount of carrots I ate..
But a nice scientific view on the amount and color of light and interference with sleep I read on the BBC website some time ago. It stated that the color is less important than the amount of light. They even found a tendency to improved sleep with blue light at a very low intensity compared to light with colors shifted to the red with very low intensity.
So that will be not the last word.....
But that's about Night Shift. I know.