flexslider_img.css in Flex Slider 7.2

/* Avoid scroll bar issues when the slider is next to the edge of the page */
.flexslider .flex-direction-nav a,
.flexslider .flex-direction-nav a {
  display: none;
}
.flexslider:hover .flex-direction-nav a,
.flexslider:hover .flex-direction-nav a {
  display: block;
}