Do you have photophobia? That is a medical symptom where the user can not endure light in his eyes. And do want to reduce the pain in your eyes against that bright white light? You can do this with the Turn Off the Lights Browser extension you can protect your eyes late at night.
Best Photophobia Health App
If you want this for your whole computer screen, and not inside the browser window such as Google Chrome. You can get the Turn Off the Lights for Desktop app that is available for Windows and Mac users. This will it automatically dims the screen when your start up your computer.