What does this button on my Ford Fiesta 2012 SE do?

What does this button on my Ford Fiesta 2012 SE do

It's the button to the right of the light knob and it has some sort of an up and down button.

2 options spring to mind. Either it adjusts the instrument panel lights or if it has 0 to 3 or 4 that is for adjusting the level of your head lights depending how many people you have on board.

Andy C

That adjusts the brightness of the instrument panel lights.