My experience with computer monitors over the past 30 years has shown me that they are not harmful to your health. The CRT was used for the first 20 years, and the tube-style monitors for the remaining 10 years.
Electronics have one major drawback: those with insomnia. I am a long-standing member of this group. After purchasing a smartphone in 2016, I discovered that blue light or blue-green light from electronic screens can make it difficult to fall asleep. It is also known to cause wakefulness, which I have experienced with my phone. This is why I use “nightmode” settings on my computer — Win10 has one, and Android 8 has one. Before Android 8, however, I used an app to do this. This makes the screens appear a bit darker and warmer in terms of the light they emit. It does help me fall asleep. About an hour before I go to bed, I turn off the computer and let it go to its default screensaver. I then read a book using the Kindle app on the phone. The screen is smaller than my 23-inch monitor so it emits a lot more light and is in warm night mode.