Well, you're all right, I definitely do need to get my eyes checked again!
(i have tried with my reading glasses but it's worse)
Anyway I took a roll today and used the prism, then the wlf with magnifyer, and then the acute mat split screen thingy and it was SO much brighter...it needs cleaning up and I definitely need to practice with it but at least I can tell if I'm focussed, at least I hope so, I'll find out tuesday. It does distract from the overall scene but it's probably something I can adjust to and really I only need to use it in low light.
Thanks for the suggestions, I wouldn't have tried it again without your recommendations.
I'll let you know how it goes :)