Dell S2330MX Monitor - Manual (Page 21)

Brightness Allows you to adjust the brightness or luminance of the backlight.
Press the key to increase brightness and press the key to decrease brightness (min 0 ~ max 100).
Contrast Allows you to adjust the contrast or the degree of difference between darkness and lightness on the monitor screen. Adjust brightness
first, and adjust contrast only if you need further adjustment.
Press the key to increase contrast and press the key to decrease contrast (min 0 ~ max 100).
Auto Adjust Use this key to activate automatic setup and adjust menu. The following dialog appears on a black screen as the monitor self-adjusts to
the current input: