Ah, vanity! I guess that's why we wear contacts or have lasik surgeries....although, Glasses can be difficult to manage in certain occupations. I can't imagine a soldier during the Civil War able to keep glasses on his face or not breaking. In fact, having myopia or presbyopia certainly created dangerous situations in battle. Presbyopia usually starts about 40ish. I wonder the age breakdown of the soldiers. I will look into the stats.

But both conditions would give a soldier (or Doc) a most difficult challenge. I have never loaded a gun or etc, but I think you would need to see close up for that task. So, the older soldiers would have had most of the presbyopia. (i.e., can't read without holding the book very close).

The myopia issue would probably be most dangerous. Just walking through a field, a soldier could fall into a ditch or trip. And most of all, a soldier would not be able to see or hit targets.

I'd bet there were not many sharpshooters wearing glasses. (not impossible).

And, the glass must have been heavy, I suppose...