When in a course you'll have a menu off to the left side of your screen with all the course options (e.g. Announcements, Grades, Discussions, etc.). Some of those items will have a crossed out eyeball icon next to them indicating that they are not visible to the students. (See below)
If you want to Enable or Disable a menu item:
- Go into the Course > Settings > Navigation
- In the Navigation window you should see 2 groups vertically arranged. The top group is Enabled and the bottom group is Disabled.
- To Enable or Disable a menu item click into the options menu (3 vertical dots) and choose to Enable or Disable the menu item
- Hit the save button at the bottom right of your screen and you are done.