Lyric discussion by thisistooshort 

Cover art for Glowing Eyes lyrics by Twenty One Pilots

I think "someone at the door" is his responsibilities and they need attention, but he wants to stay in his state of depression, as he refers to as "glowing eyes." He knows that he should be happy and that he is completely capable, but he wants to stay depressed.

And I think he's saying that if he gets a little less depressed, he'll try to stay the most depressed as possible, so he'll play a sad song "for the eyes to sing along" or in other words, stay depressed.

I think he's also saying that he knows people that are happy and their life is way better than his, so he get jealous and would rather think of ways to take his life than to think about how much better their life is than his life.

My Interpretation

ignore the weird slashes, my computer is messed up