IE8 is a real PITA, and I ended up having a Developer go through my entire site and make things work as well as possible in a variety of browsers. IE does not process media queries, I have heard, so I now have a separate ie.css sheet in my Child Theme. This might or might not fix your problem, but here is an IE function I have added:
<?php
/*
Plugin Name: IE8 PwrdFix
Description: Makes typing appear in the Password Box during IE8 Login
Version: 0.1
License: GPL
Author: _CK_
Author URI: https://ckon.wordpress.com/2009/03/19/how-to-fix-internet-explorer-8/
*/
/* function fix_ie8
# in use as of 01/02/2012 as "IE PwrdFix" (plugin)
# from: https://ckon.wordpress.com/2009/03/19/how-to-fix-internet-explorer-8/
# Make a mini-plugin out of it and activate.
#(you might be able to put it into functions.php if that executes before other data is sent but I am uncertain) */
function fix_ie8() {
if (strpos($_SERVER['HTTP_USER_AGENT'],"MSIE 8")) {header("X-UA-Compatible: IE=7");}
}
/* add_action('bb_send_headers','fix_ie8'); // for bbPress */
add_action('send_headers','fix_ie8'); // for WordPress
/* end of function fix_ie8 */
?>
In my own case, that makes the dots show up in the IE8 password box during login.