Just like the compass, a circular magnifying glass, which shows up on screen, that we can drag over any part of the game screen and magnifies what is beneath.
We're all getting a bit older, and sometimes chat text is hard to read, sometimes we can't quite see which tool is required to imp, and sometimes there's a strange 'blob' on the in game map we can't make out. We might love the way our screen is set up for most gameplay, but just sometimes we need to look a tiny bit closer at something on screen.
A floating magnifying glass could be dragged around the screen as required. It could be a real item in inventory, and could be used to start campfires during daylight hours. It could have potential uses in map reading, tracking, cyphers / code breaking or pyrography. A really useful tool.