link only on visible image

link only on visible image

The 4 images are stacked and the appearing is controlled by css changing opacity. I try to get a link on only the last one of the images. Only if the one is shown, it should be clickable. A simple link to index.html...

     <div class="fixed-top container d-block w-50 nachvorn" data-pg-name="Augen" id="LGschliessen">
                <div class="augenlogo">
                    <a href="#" >
                        <img class="augen" src="images/navbar/augen.png" alt="">
                        <img class="home" src="images/navbar/home.png" alt="home">
                        <img class="top" src="images/navbar/top.png" alt="top">
                        <img class="sv"   src="images/navbar/s+v.png" alt="">   <!-- back browser history: onClick="history.go(-1); return false;" -->
                    </a>                    
                </div>        

snote