I have a similar problem with the OM1n. I can't see the whole frame with my glasses on and I struggle to focus with them off! So what I now do is set a medium - small aperture and use the DOF scale on the lens (which is reasonable accurate on the Zuiko lenses) I tried autofocus for a while (Canon EOS50E) but foud it didn't always focus on what I wanted it to, whereas I get about a 95% success rate with the manual OM1n. Obviously, wider lenses are better for this technique in my experience.

Rob