ETA: I wrote this after judging a contest where I read 30+ self-published books.
Think about it. When have you seen eyes flash? I mean, with emotion, not because they are reflecting light. Can’t think of it happening, can you? And yet, in book after book, people have flashing eyes. They flash in anger. They flash in desire. Sometimes they flash with impish glee. Always with the flashing and the eyes.
And for that matter, eyes do not twinkle. Nor do they smolder or blaze. In fact, what does that even mean, blazing eyes? That somebody’s eyes are on fire? Also, eyes most certainly do not darken dangerously. Never in the history of the world has eye color changed from someone being angry.
And while we’re at it, eyes are rarely emerald green, okay? Unless the person is wearing colored contacts, it just doesn’t happen. So if all your characters have ivory skin and emerald green eyes, you might want to re-think that. Ditto ice-blue eyes, although I suppose that happens in nature more often than emerald-green eyes do. But really, the vast majority of people have brown eyes. Yup, plain brown, completely lacking the drama or specialness of violet or black or teal eyes. And yet, I’ve heard people say that brown eyes are actually quite lovely sometimes. Give them a chance.
Here is how eyes portray emotions: we have hundreds of muscles in our face. When we have an emotion, some of those muscles move to suggest the feeling. This can be difficult to pin down. What would shift in a face to suggest that a character is angry? Would his eyes narrow? Would he tighten his mouth slightly as he stared straight ahead? Deciding on these details will make your description vivid and grounded in reality. It will also keep you from using so many clichés.
So please, writers-of-books-Joy-is-reading, stop with the bad eye descriptions. When you’re using eyes in creative writing, make them move like human eyes actually move. Your description will be better off for it. And I, in turn, will no longer have to visualize lightning bolts shooting across your characters’ irises every time they lose their tempers.