I have been using the shield for over a year. It blocks the blue light nicely, and it is noticeable as the screens look yellowish. It also works as a privacy screen. It prevents people sitting next to me to see what’s on the screen, which is nice, except when I am trying to share what’s on my screen with another. I have to move away from the computer and face it to the other person ultimately. I Did not give it five stars because the adhesive method does not seem elegant. One has to use something similar to double sticky pieces of tape. I would buy another again.