RIP Jon Snow

It is called a ‘pupillary sphincter,’ as a matter of fact, we looked this up on the Internets and it said that your pupillary sphincter relaxes and that your eyes dilate, and if you look carefully, Jon’s pupil dilates — the one that’s in the light dilates.

--Game of Thrones co-creator D.B. Weiss in a Variety interview on the status of Jon Snow 

Update:  Of course, you know that is not the last word.  That Jon really dies is the lesser issue.  Whether Jon rises again is the real issue.  Here is another convincing view that more it to follow - see the video "Jon Snow's Return & Why It's Not Melisandre Who Brings Him Back."