You must be running Photoshop CC 2014 to have the Focus Area tool.
Are you running Photoshop CC instead?
What do you see in Help (Win) or Photoshop (Mac) > About Photoshop?
Probably. Is 2014 an update our a totally different thing?
Well, that's a more complicated question than it sounds :-)
Photoshop CC 2014 is actually a completely new version of Photoshop which is available via your Cloud membership at no extra cost. It supersedes Photoshop CC.
When installed, you'll see this in your Cloud desktop app
The Focus Area tool is a new feature found only in CC 2014.