Is there an Event triggered when the User "sees" a certain Element?

Is there an Event triggered when the User "sees" a certain Element?

Is there an Event triggered when the User "sees" a certain Element?

The case is: i want to execute an function when the user is scrolling down and reaching a certain point/element. At the moment I'm doing so by using scroll and the position of the element:

  1. $(window).scroll(function(event) {
    if($(window).scrollTop() > ($('#element').offset().top - 800) && 'true' != activeautoload){
    activeautoload = 'true';
    function_load(5);



  2. }
  3. });
But i'm not a 100% percent on this since the offset().top seems to vary from the scrollTop for reasons i don't completly understand so far. Is there a better Way then using the position and if not is there a better way using the position?