something I've always wondered; how come those 3 had the same kind of glasses?

They may have had the same eye doctor.

Perhaps they were Army issued eyeglasses!

I never heard of that!

I never noticed it either; I don't know what army-issued eyeglasses were like during the Korean War years, but while I was in (1970s and even today I think) we had very thick, black plastic frames, or as the army so aptly puts it 'TEDS'--or, Technical Eye Devices, or as the troops sometimes refer to them--'Army Issued Birth Control' :lol:

From what I've seen of them outside of M*A*S*H, Harry Morgan & William Christopher didn't wear glasses off set, so their glasses were just props. They may have had prop glasses made from the same frames as Radar's. Potter's glasses were just for reading, I think, so maybe Harry Morgan used them for the same purpose.

I know William Christopher wears them for reading cause I remember seeing somewhere once, a picture of him on the MASH set in costume and makeup reading something and he was wearing his reading glasses over his prop glasses.