I first tried varifocals around 15 years ago but didn't get on with them - though I certainly didn't have the kind of problems you are reporting and I would definitely say the prescription isn't right.
I tried varifocals again a few years later, but this time I bought the highest 'grade' (there were four grades), and I have never looked back. I wear them all the time now from the minute I get up until I go to bed and I read with them with no problem. I don't have any problems wearing them when using my laptop, but I cannot cope with them when using my desktop, because of the angle of view - I found I was having to tip my head back so that I could look through the reading section at the bottom of the lenses. So I bought reading glasses and just leave them next to the desktop as I never use them for anything else.
Oh, and I have had excellent varifocals from Specsavers and from Boots, with nothing to choose between them.
Someone I know shouldn't be driving. In my opinion.
“We start school too early in the UK!”
