Have you ever noticed that when one videotapes a television program, that
often the picture on the video comes out as moving up and down but was
normal while being watched? I have wondered what possible subconscious
effect this may have.
Well I also noticed one day, when I walked away from the computer, that on
coming back and chancing to look at the screen through a glass window
(several feet away from the computer) which had decorative lines on it, that
behind these lines the screen was definitely vibrating. This I had not
noticed before while sitting right in front of it. It is especially
pronounced when the screen has a lot of white on it at the time.
For fun try videotaping the LCD of a stereo set or other electronic device
then play it back. On the video the LCD will be moving rhythmically...
The "vibrations" that you saw when you were behind a window with
decorative lines were no doubt a result of your moving eyes, a
refreshing screen, and the lines. Even if you think you are
staring steadly, your eyes are continuously in motion. They have
a very small amplitude, rapid "jitter" and drift, and when they
drift off target, they will jerk back (saccades). You're
generally unconscious of all of this.
Each time the screen refreshes, your eye is very likely in a
different position with respect to the screen. The static lines
on the window give a reference point, making it appear that the
screen was moving or vibrating.
FurPaw