“Thousand-yard Stare” by Tom Lea 1945.

Tom_Lea_-_2000_Yard_Stare
The phrase was popularized after Life magazine published the painting Marines Call It That 2,000 Yard Stare by World War II artist and correspondent Tom Lea, although the painting was not referred to with that title in the 1945 magazine article.
The painting, a 1944 portrait of a Marine at the Battle of Peleliu, is now held by the United States Army Center of Military History in Fort Lesley J. McNair, Washington, D.C. 
About the real-life Marine who was his subject, Lea said:
He left the States 31 months ago. He was wounded in his first campaign. He has had tropical diseases. He half-sleeps at night and gouges Japs out of holes all day.
Two-thirds of his company has been killed or wounded. He will return to attack this morning. How much can a human being endure?
via Thousand-yard stare – Wikipedia, the free encyclopedia.