As I explain in the Brightness article most monitors use method for controlling the brightness called Pulse Width Modulation which is really bad for the eyes. Iris uses it’s own special innovative brightness which reduces your brightness without introducing flicker to your monitor.
Note that under Windows there is limitation of this color changes by default and Iris will prompth you to Expand your color range on the initial calibration.
With the new versions of Iris this expanding is automatic and you just need to restart your computer once after the first Iris installation.
If some of the values on this dropdown are unavailable chanses are you need to Expand your system color range.
By default also Iris will apply the brightness manually, but you can make the brightness to low gradually at night by setting Manual brightness to OFF.
After every change remember to click Save and close otherwise all changes will be reverted to the last saved state.
If you wonder what value should you use from your brightness, the rule is that it should match your room lighting. For example at night I use it on 75% when the lighting is ON and on 45% when the lighting is OFF.
Iris also has the option to use AI and your camera to automatically adjust your screen brightness based on the lighting, but this is options is disabled by default as some users find it creepy if their camera is working.
I am working also on using the integrated light sensor on some laptops, but this feature is still not ready.