Doesn't constant icons in dock or top-bar cause to screen burn-in?

Solution 1:

It obviously depends on the model of the screen, but I've never seen a screen burn-in problem occur on static areas of the screen of any monitor or screen that I've ever used with Ubuntu. I normally lock the screen and turn off the monitor when I'm away from the screen for more than a minute or two in order to save power and prevent screen burn-in. It should also be noted that energy efficient screens have a longer lifespan than a non-energy efficient screens as well as using less energy when drawing power from a battery.