‘Jon Snow is dead’, Game of Thrones showrunners David Benioff and Dan Weiss tell Variety. The duo revealed that they spent a lot of money to ensure that Kit Harington had the eyes of a dead person, when his character was murdered by the men of the Night’s Watch in season 5 finale:
“People are spending a lot of time looking at his eyes, thinking he’s not dead,” reveals Benioff. “We spent a lot of time …”
“We spent a lot of money on his eyes. Pupillary muscles relax when your body gives up. It is called a pupillary sphincter. We looked this up on the Internet. Your pupillary sphincter relaxes and your eyes dilate. So you look carefully, Jon’s eye dilate.”
Benioff gives a rather bizarre comparison:
“People fart when they die because muscles relax and they release the gas. Same mechanism.”
You can watch the interview below.