You can customize the menu items on the left-side of your course page for students. To do this:
In Course Navigation, click the Settings link.
Click the Navigation tab.
You can use the drag and drop option to reorder navigation links. Click the navigation link you would like to move. Drop the navigation link in the desired location by releasing the mouse.
The icon with the crossed-out-eye indicates that these items are not visible to students.
These crossed-out-eye icons appear either when there is no content in the item, or if the item is hidden from view. In the latter scenario use the steps above to make the item visible.
This same navigation menu would look like this in student view: