How to adjust your monitor brightness while using internet?

One of the obvious thing that can show the strain of watching at your computer for a long time is your eyes. That can be really harmful for your eyes because of it can reduce your vision forever.  Therefore, as a solution we have to use some tricks to protect our eyes. In modern laptops have 2 or many buttons to adjust your brightness and contrast. But desktop users can not control your monitors brightness using keybord. (some time it can be done using your LCD settings) 

Therefore as a solution you can use an extension to do this manually while using internet. If you use Google chrome or coolnavoo as your browser you can use this extension.  You can add this extension to your Google chrome browser within the link given below. 
 Add Extension to Google Chrome.