This a a very strange and pedantic approach, which IMO does not add much to the discussion
because this insistence that you can identify a psychopath by their eyes is blatantly untrue, and incredibly unhelpful.
My cat is gazing at me steadily right now. Depending on MY preference, I could interpret that look as loving, warm, hungry for dinner, or cold and dead.
A lot of what is being described here is not really anything to do with genuine psychopathy.
"I thought he was nice, now he is being horrible, so he must be a psychopath, and he's got dead eyes so that proves it"
I suspect a lot of these exes would be saying the same thing about the posters!
Psychopaths are not cold eyed, they are not necessarily clever, charming, handsome, lethal,
Many of them are conceited, not as bright as they think, and typically a large number are overweight.