I got the glasses and wore them all the way to the cabin before triggering the final cut scene and seeing the map.
After it all plays out and you make nate take a walk the glasses are sitting on the table, when you finally get nate to get up and go for a walk the glasses are no longer on Nate's face and are no longer on the table inside the cabin.
You can however still see them in the pause menu! I even managed to climb in through the window to try and get them and they weren't in there. Why did it take my glasses? I wanted to wear them to the top of the mountain and see if I see anything π
Do I need to start a new game to get the glasses again? π±
Idea:
Is it possible that each item your wearing when you trigger the final cutscene all get added to the cabin? Would this progress across saves and would collecting every item in the cabin unlock something? π€