If you are using the classic theme of Windows 7/Win 10, then you will not be able to use the Reading mode of CareUEyes and you will get a warning message when using the Reading mode of CareUEyes.
You need to enable the Aero theme to be able to use the reading mode.
How to enable the Aero theme?
1. Ensure that your version of Windows 10/8/7 supports Aero. Aero is supported on Ultimate, Home Premium, Business editions.
2.Ensure that your Graphic card supports WDDM (Windows Display Driver Model)
3. Right click on the desktop, pop-up menu select “Personalize“, select related topics in the “Aero Themes” area, these topics are all with Aero features
4. Open CareUEyes, reselect “Editing” or “Reading” Mode