Can I use icons to indicate state?

I am working on a web product that deals with music education. Teachers can give assignments and attach instructions to that assignment.

Not every assignment will have instructions attached to it. So the first icon next to "assignment name" will indicate that there were indeed instructions attached to an assignment, and the second will indicate that the student actually looked at it.

The question is whether the state should be indicated by placing additional icons, or whether we can indicate the state with the word itself?