Facebook users know how to set options to limit audience to their profile or posts via "Who can see my stuff" option from the Settings option. But here I am not discussing that option here. A start to say that users can limit their audience either to "Public" or Private" or "Friends" etc. 
Either you can use Facebook Apps to check the profile visitors or there is another way to deal with it. That is installing the Extensions or Add - On's for a specific browser. Depending upon the browser you are using, you can install that add on and instantly get notified.

For Firefox users : If you are using Firefox, then an add on called "iFrameBook" is useful for information of who is visiting your profile. This add on is completely free to download.

 Steps to download iFrameBook for Mozilla Firefox:

Please note that if your friend also has installed this add on on his or her browser then it is possible for you to know that he has visited your profile. 
For Google Chrome users : If you are having Chrome, then you can have this extension called "Profile Visitors". 
This extension is for Firefox and Chrome both browsers. To get it for Chrome, 
  • Go to the link Profile Visitors
  • Select the option Chrome from the drop down list
  • Then click "Activate" button  
Facebook App Profile Visitors: There is another way to find out the profile visitors. An app called ProfileVisitors2013  will help you. 
When you visit the link, you will be directed to a Facebook page. On that you have to click on the link from About section. The link will direct you to the download link. 
Any way you use or any browser you use, there is a possibility of finding out the profile visitors of your Facebook account. To keep your account safe and secured from hackers, this is very necessary step. People may hack or get the details which are not shown on your profile. 
So, get it secured by downloading an add on.