Are you writing an original character for Fanfiction? Here's a bit of advice: be careful and consistent with this trope if you want anybody else to take the character seriously. This is often lumped as a Mary Sue trait. Sometimes referred to as Mood Ring Eyes, this trope refers to when the character's eyes change on their own. Contact lenses or false/prosthetic eyes for a blind character do not count. Ethereal or otherworldly characters tend to have this trait.