SCSS - IE8 Opacity mixin

opacity-mixin.scss

@mixin opacity($opacity) {
 // @if $legacy-support-for-ie6 or $legacy-support-for-ie7 or $legacy-support-for-ie8 {
    // -ms-filter: unquote("progid:DXImageTransform.Microsoft.Alpha(Opacity=#{round($opacity * 100)})");
  //}
  filter: alpha(opacity= round($opacity * 100)); /* internet explorer */
    opacity: $opacity;           /* fx, safari, opera, chrome */
    -ms-filter: unquote("progid:DXImageTransform.Microsoft.Alpha(Opacity=#{round($opacity * 100)})");
    //-ms-filter:"progid:DXImageTransform.Microsoft.Alpha(opacity=50)"; /*IE8*/
}