scopesurfr, thank you for your observations (no pun intended). I think I realised quite quickly that the style of glasses, and shape/thickness of frame are important. Unfortunately, the very obvious solution of taking my glasses off is not something I'm prepared to do during everyday viewing. That said, I did experiment without my glasses, when trying to establish whether or not I was getting the full field of view with my glasses on, and found the kidney beans difficult to eradicate even without glasses on. I got there eventually, but the experience reinforced how precise you need to be when setting up this magnification format.
Patudo, thank you, and yes, a very tricky one as it turns out. I have been reluctant to twist the eyecups up, because if I do, I am unable to see the full field of view, something I find almost as irritating as those kidney beans, I do like to be aware of the crisp edge of the field of view when viewing. And, in order to get the full field of view, my glasses need to be sitting right at the top of the bridge of my nose, as close as possible to my eyes. I do, in fact, have access to 6 pairs of glasses, three with my current prescription and three with my older prescription from around eight years ago, one of each prescription being sunglasses. There is one pair of each prescription which work best with the instrument. Of those two, the ones with my new prescription appeared to work well with the bins last Thursday, the ones with my old prescription worked almost as well on Friday, I mixed things up and tested with all my glasses on Saturday, with varying degrees of success, then yesterday I had issues with absolutely all of them...which is why I came here for advice.
I really (,really, really) love these bins in the hand, so light, balanced and ergonomically natural in how they handle in use. The optics are just so crisp, low light performance belies their 32mm aperture, and I'm completely blown away by the focus mechanism, the wheel placement, the smoothness of operation, the speed and precision of the focus, absolutely second to none. And, because of their size and weight, they're easy to adjust if you don't get your positioning right first time...it's just that sometimes I find it impossible to actually find that correct position. In terms of their size, weight and performance, they are an absolute dream binocular for when you're out walking/hiking... BUT incredibly challenging/frustrating when you can't position them.
I'll experiment further, this morning, with both the eyecup positioning and with whereabouts my glasses sit on my nose. Whether I can find that sweet spot with full field of view and no blackouts remains to be seen, I have my doubts, but I did manage it for most of last Thursday, so I have to assume it's possible, although it may be that I perceived I was getting the full field of view, when in fact I wasn't.
I'm definitely having a love-hate relationship with these binoculars so far...