Some laptops have function keys that can be used to adjust screen brightness. These may not be supported on all laptops, however. In that case, there may be the controls in monitor settings or power management to adjust the brightness.
In my case I wasn't able to find anything, so I discovered how to adjust this using a command line setting. Install the xbacklight package and then invoke it with a command like this
xbacklight
By itself, this will give you the current reading.
xbacklight -set <x>
Pass some number after the -set parameter and it will set the brightness. I found 50 to be a good number after discovering the default is just 12.5.