I just used a pair of calipers to measure the width of the bridge of my nose where eyeglasses nose pads would rest. It's just over one inch, and that was squeezing pretty hard on bone.

Comparing that to a pair of safety glasses lying around work shows that the bridge doesn't get that wide until below the nose rest area. This means that I can either move the glasses way up my face or have the sit far away from my face.

The little arms on nose pads tend not to be long enough to move far enough to the side, so they also have to be moved up, which puts them just in the edge of my field of vision, and near enough to my tear ducts as to make them wildly uncomfortable.

Both of my pairs of prescription glasses are the sort that are metal frames with no nose pads, and rest solely on the top of the bridge of my nose.