Why do things look fuzzy/pixelated on my screen?
This can happen because the display resolution that you have set it is not the right one for your screen.
To solve this, open the Activities overview and start typing Displays. Click on Displays to open the panel. Try some of the Resolution options and set the one that makes the screen look better.
When multiple displays are connected
If you have two displays connected to the computer (for example, a normal monitor and a projector), the displays might have different resolutions. However, the computer’s graphics card can only display the screen in one resolution at a time, so at least one of the displays might look fuzzy.
You can set it so that the two displays have different resolutions, but you will not be able to display the same thing on both screens simultaneously. In effect, you will have two independent screens connected at the same time. You can move windows from one screen to another, but you cannot show the same window on both screens at once.
To set up the displays so that they each have their own resolution:
Open the Activities overview and start typing Displays.
Click on Displays to open the panel.
The displays should be listed as Mirrored. Select your main display.
Select Primary in the list of display configurations, and then click Apply to save.
Select each display in turn from the gray box at the top of the Displays window. Change the Resolution until that display looks right.