These crystal lenses fit over the eyes. While wearing them, you can see much better than normal out to a range of 1 foot. You have advantage on Intelligence (Investigation) checks that rely on sight while searching an area or studying an object within that range.
RollQuest ships the D&D 2014 SRD as a content pack, on a 5e character sheet that does the maths - roll from the sheet and let the numbers work themselves out. Free to start.