I wear reading glasses so that I can read and also to see deep into cells. When wearing the glasses I cannot focus on more than a foot away. The other day, during a dearth period, a pesky big blackish wasp kept trying to gain entrance into a hive. It would come near the entrance, I'd smoke it, and it would retreat. However, it really wanted in and kept coming back. After the third smoking/retreat sequence I had to take the glasses off to clearly see what this bug was all about. It turns out this was not a wasp but a very nice sized queen bee returning from a mating flight. Glasses are good but mated queens are better...The hive is now thriving.