Too often windows screen are too bright even if they are at their lowest setting. While some of them maybe comfortable with the brightness, it becomes really uncomfortable for a user who is working at night constantly and it may damage your vision.
To combat this I have my personal favourite tool called pango brightness. It can be downloaded from the following website.
With this tool you can further decrease your brightness and add a darker shade to your screen in different tones. You can also choose your own custom color making it very customizable.