Camera View finders

I too have this problem of trying to look through the viewfinder and not
being able to focus. I wear glasses, so when looking through the
viewfinder, I look over the top of the glasses. I have a Canon 700D and it
is hopeless. I read that the viewfinders on the Canons are -1 to +1 Dioptic
range, which is a pretty useless range. I can turn the dial as far as I can
and still have everything blurred.
My cheaper Panasonic Lumix has a dioper range of -4 to +4, which allows me
to see perfectly.
To solve my Canon problem, I have bought a +3 Dioptic lens which slips over
the eyepiece. This has improved my vision a bit, but it is still not clear.
I obviously need a + 4 or +5 – which they do not make.
I have now bought another +1.5 Dioptic lens, which when received, will
stick it to the front of the +3 Diopic Lens in the hope that I can see
through my viewfinder.
It would be so much easier if Canon could just follow Panasonic’s example
and make a viewfinder with a more decent dioptic range.
Carol Abbott