Andrew Huberman· PhD
In the evening, you see the evening light and you want to get that light to adjust down your retinal sensitivity to afford you a bit of a buffer so that late at night, if you happen to look at screens or go to the bathroom in the middle of the night, it's not going to shift your clock because it takes probably only about 1,000 to 1500 lux of light energy to shift your clock in the middle of the night.