Element.Methods.isVisible = (function() {

  function ancestry(element){
    var ancestors = [element];
    while(ancestors.last() !== document.body)
      ancestors.push(element = element.parentNode);
    return ancestors;
  }

  function getAncestricStyles(element, style){
    return ancestry(element).invoke('getStyle', style);
  }

  function isVisible(element){
    return !(
      getAncestricStyles(element, 'display').include('none')      ||
      getAncestricStyles(element, 'opacity').include('0')         ||
      getAncestricStyles(element, 'visibility').include('hidden') ||
      getAncestricStyles(element, 'height').include('0')          ||
      getAncestricStyles(element, 'width').include('0')
    );
  }

  return isVisible;
})();