Oh heck ...Yep that will do it every time !! I think that's why my head is aching ....its trying to position my head right for my new varifocals....amongst other things
it's taken me weeks to work it out...I get up and I'm fine, after I've had a coffee in the garden I'm walking like a St Bees crab
Hope you soon get used to the varifocals...I've never once had a problem and you shouldn't be positioning your head...just use your eyes to find the correct balance *smacks hand*