jQuery: Check if element is in designated area of viewport (horizontal)

element-in-viewport.js

function toggleDecadeVisibility() {
  var windowWidth = $(window).width();

  $('.element').each(function() {
    var elementLeft = $(this).offset().left,
        visibleOffset = (windowWidth / 2) - ($(this).width() / 2),
        hideOffset = visibleOffset - $(this).width();

    // If element is in center of viewport, make visible
    if (elementLeft <= visibleOffset && elementLeft >= hideOffset) {
      $(this).addClass('element-visible');
    } else {
      $(this).removeClass('element-visible');
    }
  });
}