Let's have a look and see if any more of their story can be puzzled out.
The binoculars have seen a bit of use and wear, but are actually in good working order. Clearly this was a quality built bit of equipment.
The internet is really quite helpful on this kind of question, so these markings on the binoculars proper, helped a lot. "Dienstglas" translates literally to "Service Glass" meaning a shatter resistant, high quality lens for military use. The numbers relate to the magnification factor. The designation blc was the code for the Carl Zeiss factory in Jena. Zeiss then and now were among the world's leaders in optical lenses.
Although the above strongly suggests military binoculars the confirmation was actually on the leather case.
Note the date, 1942. The Eagle and swastika logo has beneath it another code. Unfortunately part of it is worn off as that is where the clasp rests. WaA stands for "WaffenAmt". This was the organization responsible for weapons procurement. Stamps of this sort were placed on items during their manufacture. They indicated that the item had been made to correct specifications. Very tentatively I think the numbers that follow "might" be 14, which would mean the case was made at the Curt Vogel leather works factory in Cottbus.
To make things just a little more confusing the metal clasp has another code on it. This looks to be frn42. frn indicated the Federn-Draht und Metallwarenfabrik in Havel.
So, we have a pair of German military binoculars made in 1942. But how did they get to Indiana? One must assume that an American serviceman acquired them overseas and brought them back. This is a good example of how provenance - the documented history of an item - is everything. Were these taken from a captured officer on D-Day? Or bought at a flea market twenty years later? The glasses and case show signs of considerable use. But was it with the Afrika Korps or on the outskirts of Stalingrad? Or was this a brand new pair when some farm boy from Indiana grabbed them out of a warehouse, then faithfully took them duck hunting for many seasons?
As a side note German binoculars are a pretty common thing to find be it on ebay or perhaps at a modern day flea market. They were the sort of thing that was avidly sought after and the US military's restrictions on taking home items such as firearms did not impede the spiriting off of this kind of souvenir.