Jagged edges on all vector paths in Illustrator CC2015

Since updated to the newest versions, all my vectors appear jagged. Nothing looks smooth. When exporting them, they are fine. But it makes it extremely difficult to work when you're applying things like rough edges, and textures because you can't make any sense of what is happening. Here is an example:

Those are straight lines, yet they have the staircase effect.

I've tried:

• Cmd + E
• Turning off GPU performance
• Updating my operating system
• Updating anything Adobe related

I know it's not my computer because everything else looks crystal clear in broswer, etc. so it cant be a graphics card issue..

Any suggestions?

Thanks,