Alienware AW3821DW 37.5" 1600p 144 Hz Curved Gaming Monitor - Manual (Page 45)

Operating the monitor | 45
Brightness/
Contrast
Use this menu to activate Brightness/Contrast
adjustment.
Brightness Brightness adjusts the luminance of the backlight.
Move the joystick right to increase the brightness level
or move the joystick left to decrease the brightness
level (min. 0 / max. 100).
Contrast Adjust Brightness first, and then adjust Contrast only if
further adjustment is necessary.
Move the joystick right to increase the contrast level or
move the joystick left to decrease the contrast level
(min. 0 / max. 100).
The
Contrast function adjusts the degree of difference
between darkness and lightness on the monitor screen.