Yes, forcing vsync is the solution, at the expense of 1-2 fps.

0. close FFXIV and go to your nvidia control panel

1. click on manage 3D settings

2. add ffxivgame.exe to the list

3. scroll down untill you see the vsync option and set it to "force on"

4. click apply, restart your FFXIV client

The tearing should be gone now. It works fine for me.

This is what I found on FFXIVcore site, it may help, search on google, you may find some other advise.