Unable to add an icon at left of an input box in twitter bootstrap

I am designing a login page here and I want to add the icon glyphicon-eye-open inside the password input field on the right, but I am unable to do so.

I tried putting it inside .has-feedback but it didn't work.
I tried the solution to Add Bootstrap Glyphicon to Input Box, but that didn't work as well.

There might be an external style-sheet causing the problem, but I'm unable to fix it.

Using bootstrap's native validation states is definitely preferable to writing custom CSS here.

When using .has-feedback, make sure you also add the class .form-control-feedback to the glyphicon. It should look like this:

<!-- language: lang- html --> <pre><code>&lt;div class=&quot;form-group <b>has-feedback</b>&quot;&gt; &lt;label class=&quot;control-label&quot;&gt;Username&lt;/label&gt; &lt;input type=&quot;password&quot; class=&quot;form-control&quot; placeholder=&quot;Password&quot; /&gt; &lt;i class=&quot;glyphicon glyphicon-eye-open <b>form-control-feedback</b>&quot;&gt;&lt;/i&gt; &lt;/div&gt; </code></pre>

Demo in jsFiddle

For more info, see my answer to adding a Bootstrap Glyphicon to Input Box