Safety and Comfort
You may find a range of monitor heights that allows your head to be balanced comfortably over your shoulders.
Monitor
You will reduce eye strain and muscle fatigue in your neck, shoulders, and upper back by properly positioning your monitor and adjusting its angle.
Positioning the Monitor
Place the monitor directly in front of you. To determine a comfortable viewing distance, stretch your arm toward the monitor and notice the location of your knuckles. Place your monitor near that location. You should be able to clearly see the text on your monitor.
Adjusting the Monitor Height
Your monitor position should allow your head to be balanced comfortably over your shoulders. It should not cause your neck to bend forward uncomfortably or backward to any degree. You may find it more comfortable to position the monitor so that the top line of text is just below your eye height. Your eyes should look slightly downward when viewing the middle of the screen.
Many computer designs allow you to place the monitor on top of the system unit. If this places the monitor too high, you may want to move the monitor to the desktop. On the other hand, if the monitor sits on your work surface and you feel any discomfort in your neck or upper back, the monitor may be too low. In that case, try using a thick book or a monitor stand to raise the monitor.