There is a common claim that, by looking into the face or eyes of a person, you can see that they have seen combat, or other traumatic events. It is particularly mentioned in movies, songs and poems.
Movie: The Objective - an old man tells a soldier he can see the desert in his eyes.
Poetry: A Soldier's Eyes by Johnny Hutcherson
Essay: The Eyes Of A Soldier by William Douglas Roser, I.
Are there any studies that show if you can indeed see in one's eyes his (traumatic) experiences. If so, is it general trauma, or is it possible you can detect "the desert", "the combat", "killing", etc... in the eyes or face?