Mine is BenQ monitor. What's the use of this Senseye effect?

Senseye magic color technology itself has been designed inside the display and has been turned on. Turn on the magic color function, mainly to show the preview effect that the magic color technology can achieve. This function can only be turned on or off when the display image mode is non-standard mode.

Simply put, things displayed on the screen are more vivid and full of colors.