<link href="//maxcdn.bootstrapcdn.com/bootstrap/3.3.0/css/bootstrap.min.css" rel="stylesheet" id="bootstrap-css">
<script src="//maxcdn.bootstrapcdn.com/bootstrap/3.3.0/js/bootstrap.min.js"></script>
<script src="//code.jquery.com/jquery-1.11.1.min.js"></script>
<script src="https://use.fontawesome.com/fd9dba5260.js"></script>
<div class="input-group" style="width: 49%;">
<input value="This my password" id="password_show" type="password" class="form-control">
<span style="width:0%" id="password_show_button" class="input-group-addon"><i class="fa fa-eye-slash" aria-hidden="true"></i></span>
</div>