Originally Posted by jring
probably your glasses are quite close to the eye - in that case it is possible that you need some eyecup extension.
Btw. I don't wear glasses and have some pairs I use with the eyecups only partially extended - that's why they're adjustable after all.
Joachim is right. Until I got my current spectacles all of my binos were OK used with the eyecups fully down, but my 'new' spectacles are frameless and have thin lenses and my eyes are a bit closer to the eyepieces. With some binos I now need the eyecups up one position.
Moving your spectacles a tiny distance up or down your nose can create this situation too.
If adjusting your eyecups solves the problem then all is well.