They are difficult, and they are very tiny. If you need glasses for reading, you will need to wear them for spotting eggs. I find it helps to hold up a frame so that the light from the sun is shining from behind my shoulder, directly into the cells. Look in an area which has very small uncapped larvae in it.
The top photo in @JeffH’s post shows a beautiful queen, but if you look very carefully, you see an egg in the centre of each cell behind the queen: