WordPress ie8 Conditional CSS

functions.php

<?php

//* IE8 condital stylesheet
add_action( 'wp_enqueue_scripts', 'print_my_styles' );
 
function print_my_styles() {
    global $wp_styles;
    wp_enqueue_style( 'ie8', get_stylesheet_directory_uri() . '/ie8.css' );
    $wp_styles->add_data( 'ie8', 'conditional', 'lt IE 9' );
}